# Scalar functions

## Numeric functions¶

### `ABS`¶

Since: 0.1.0
`1`
``````ABS(col1)
``````

Returns the absolute value of `col1`.

### `ACOS`¶

Since: 0.28.0
`1`
``````ACOS(col1)
``````

Returns the inverse (arc) cosine of `col1`, in radians. Use the DEGREES function to convert the output to degrees.

This function returns `NaN` for any input outside [-1, 1].

### `ASIN`¶

Since: 0.28.0
`1`
``````ASIN(col1)
``````

Returns the inverse (arc) sine of `col1`, in radians. Use the DEGREES function to convert the output to degrees.

This function returns `NaN` for any input outside [-1, 1].

### `AS_VALUE`¶

Since: 0.9.0
`1`
``````AS_VALUE(keyColumn)
``````

Copies a row's key column into the row's value.

Example
```1
2
3
4
5
6
7```
``````CREATE TABLE AGG AS
SELECT
ID,                  -- this is the grouping column, which is stored in the message key.
AS_VALUE(ID) AS ID2  -- this creates a copy of ID, named ID2, which is stored in the message value.
COUNT(*) AS COUNT
FROM S
GROUP BY ID;
``````

See AS_VALUE in action

### `ATAN`¶

Since: 0.28.0
`1`
``````ATAN(col1)
``````

Returns the inverse (arc) tangent of `col1`, in radians. Use the DEGREES function to convert the output to degrees.

### `ATAN2`¶

Since: 0.28.0
`1`
``````ATAN2(y, x)
``````

Returns the inverse (arc) tangent of `y / x`. This is equivalent to the angle theta when Cartesian coordinates (x, y) are converted to polar coordinates (radius, theta). The returned value is in radians. Use the DEGREES function to convert the output to degrees.

If `x` is zero, `y / x` is undefined, and this function returns the approximate value of a multiple of π/2.

### `CAST`¶

Since: 0.1.0
`1`
``````CAST(COL0 AS BIGINT)
``````

Converts one type to another. The following casts are supported:

from to notes
any except `BYTES` `STRING` Converts the type to its string representation.
`VARCHAR` `BOOLEAN` Any string that exactly matches `true`, case-insensitive, is converted to `true`. Any other value is converted to `false`.
`VARCHAR` `INT`, `BIGINT`, `DECIMAL`, `DOUBLE` Converts string representation of numbers to number types. Conversion will fail if text does not contain a number or the number does not fit in the indicated type.
`VARCHAR` `TIME` Converts time strings to `TIME`. Conversion fails if text is not in `HH:mm:ss` format.
`VARCHAR` `DATE` Converts date strings to `DATE`. Conversion fails if text is not in `yyyy-MM-dd` format.
`VARCHAR` `TIMESTAMP` Converts datestrings to `TIMESTAMP`. Conversion fails if text is not in ISO-8601 format.
`TIMESTAMP` `TIME`, `DATE` Converts a `TIMESTAMP` to `TIME` or `DATE` by extracting the time or date portion of the `TIMESTAMP`.
`DATE` `TIMESTAMP` Converts a `DATE` to `TIMESTAMP` by setting the time portion to `00:00:00.000`
`INT`, `BIGINT`, `DECIMAL`, `DOUBLE` `INT`, `BIGINT`, `DECIMAL`, `DOUBLE` Convert between numeric types. Conversion can result in rounding
`ARRAY` `ARRAY` (Since 0.14) Convert between arrays of different element types
`MAP` `MAP` (Since 0.14) Convert between maps of different key and value types
`STRUCT` `STRUCT` (Since 0.14) Convert between structs of different field types. Only fields that exist in the target STRUCT type are copied across. Any fields in the target type that don't exist in the source are set to `NULL`. Field name matching is case-sensitive.

See CAST in action

### `CEIL`¶

Since: 0.1.0
`1`
``````CEIL(col1)
``````

Returns the the smallest integer value that's greater than or equal to `col1`.

### `COS`¶

Since: 0.28.0
`1`
``````COS(col1)
``````

Returns the cosine of `col1`. `col1` is in radians. Use the RADIANS function to convert the input to radians, if necessary.

### `COSH`¶

Since: 0.28.0
`1`
``````COSH(col1)
``````

Returns the hyperbolic cosine of `col1`. `col1` is in radians. Use the RADIANS function to convert the input to radians, if necessary.

### `COT`¶

Since: 0.28.0
`1`
``````COT(col1)
``````

Returns the cotangent of `col1`. `col1` is in radians. Use the RADIANS function to convert the input to radians, if necessary.

This implementation returns a large value approaching positive or negative infinity near the asymptotes, because and similar values cannot be represented exactly. At 0, it returns `Infinity` with the same sign as the input.

### `DEGREES`¶

Since: 0.28.0
`1`
``````DEGREES(col1)
``````

Converts `col1` from radians to degrees.

### `ENTRIES`¶

Since: 0.6.0
`1`
``````ENTRIES(map MAP, sorted BOOLEAN)
``````

Creates an array of structs from the entries in a map. Each struct has a field named `K` containing the key, which is a string, and a field named `V`, which holds the value.

If `sorted` is true, the entries are sorted by key.

### `EXP`¶

Since: 0.6.0
`1`
``````EXP(col1)
``````

Returns the exponential of `col1`, which is e raised to the power of `col1`.

### `FLOOR`¶

Since: 0.1.0
`1`
``````FLOOR(col1)
``````

Returns the largest integer value that's less than or equal to `col1`.

### `GENERATE_SERIES`¶

Since: 0.6.0
```1
2```
``````GENERATE_SERIES(start, end)
GENERATE_SERIES(start, end, step)
``````

Constructs an array of values between `start` and `end`, inclusive.

Parameters `start` and `end` can be an `INT` or `BIGINT`.

`step`, if supplied, specifies the step size. The step can be positive or negative. If not supplied, `step` defaults to `1`. Parameter `step` must be an `INT`.

### `GEO_DISTANCE`¶

Since: 0.6.0
`1`
``````GEO_DISTANCE(lat1, lon1, lat2, lon2, unit)
``````

The great-circle distance between two lat-long points, both specified in decimal degrees. An optional final parameter specifies `KM` (the default) or `miles`.

### `GREATEST`¶

Since: 0.20.0
`1`
``````GREATEST(col1, col2, …)
``````

Returns the largest non-null value from a variable number of comparable columns.

If comparing columns of different numerical types, use CAST to first cast them to be of the same type.

### `LEAST`¶

Since: 0.20.0
`1`
``````LEAST(col1, col2, …)
``````

Returns the smallest non-null value from a variable number of comparable columns.

If comparing columns of different numerical types, use CAST to first cast them to be of the same type.

### `LN`¶

Since: 0.6.0
`1`
``````LN(col1)
``````

Returns the natural logarithm of `col1`, which is .

The value of `col1` must be greater than 0.

### `PI`¶

Since: 0.28.0
`1`
``````PI()
``````

Returns an approximate value of π.

### `RADIANS`¶

Since: 0.28.0
`1`
``````RADIANS(col1)
``````

Converts `col1` from degrees to radians.

### `RANDOM`¶

Since: 0.1.0
`1`
``````RANDOM()
``````

Returns a random `DOUBLE` value between 0.0 and 1.0.

### `ROUND`¶

Since: 0.1.0
```1
2```
``````ROUND(col1)
ROUND(col1, scale)
``````

Rounds a value to the number of decimal places specified by `scale`.

If `scale` is negative, the value is rounded to the right of the decimal point.

Numbers equidistant to the nearest value are rounded up, in the positive direction.

If the number of decimal places is not provided, it defaults to zero.

### `SIGN`¶

Since: 0.6.0
`1`
``````SIGN(col1)
``````

Returns the sign of `col1` as an `INTEGER`:

• -1 if the argument is negative
• 0 if the argument is zero
• 1 if the argument is positive
• `null` argument is `null`

### `SIN`¶

Since: 0.28.0
`1`
``````SIN(col1)
``````

Returns the sine of `col1`. `col1` is in radians. Use the RADIANS function to convert the input to radians, if necessary.

### `SINH`¶

Since: 0.28.0
`1`
``````SINH(col1)
``````

Returns the hyperbolic sine of `col1`. `col1` is in radians. Use the RADIANS function to convert the input to radians, if necessary.

### `SQRT`¶

Since: 0.6.0
`1`
``````SQRT(col1)
``````

Returns the square root of `col`.

### `TAN`¶

Since: 0.28.0
`1`
``````TAN(col1)
``````

Returns the tangent of `col1`. `col1` is in radians. Use the RADIANS function to convert the input to radians, if necessary.

This implementation returns a large value approaching positive or negative infinity near the asymptotes, because π/2 and similar values cannot be represented exactly.

### `TANH`¶

Since: 0.28.0
`1`
``````TANH(col1)
``````

Returns the hyperbolic tangent of `col1`. `col1` is in radians. Use the RADIANS function to convert the input to radians, if necessary.

## Collections¶

### `ARRAY`¶

Since: 0.7.0
`1`
``````ARRAY[exp1, exp2, …]
``````

Constructs an array from a variable number of inputs.

All elements must be coercible to a common SQL type. For more information, see Implicit type coercion.

### `ARRAY_CONCAT`¶

Since: 0.21.0
`1`
``````ARRAY_CONCAT(array1, array2)
``````

Returns an array representing the concatenation of both input arrays.

Returns `NULL` if both input arrays are `NULL`. If only one argument is `NULL`, the result is the other argument.

Examples
```1
2```
``````ARRAY_CONCAT(ARRAY[1, 2, 3, 1, 2], [4, 1])  => [1, 2, 3, 1, 2, 4, 1]
ARRAY_CONCAT(ARRAY['apple', 'apple', NULL, 'cherry'], ARRAY['cherry'])  => ['apple', 'apple', NULL, 'cherry', 'cherry']
``````

### `ARRAY_CONTAINS`¶

Since: 0.6.0
`1`
``````ARRAY_CONTAINS(ARRAY[1, 2, 3], 3)
``````

Given an array, checks if a search value is contained in the array.

Accepts any `ARRAY` type. The type of the second param must match the element type of the `ARRAY`.

See ARRAY_CONTAINS in action

### `ARRAY_DISTINCT`¶

Since: 0.10.0
`1`
``````ARRAY_DISTINCT([1, 2, 3])
``````

Returns an array of all the distinct values, including `NULL` if present, from the input array.

The output array elements are in order of their first occurrence in the input.

Returns `NULL` if the input array is `NULL`.

Examples
```1
2```
``````ARRAY_DISTINCT(ARRAY[1, 1, 2, 3, 1, 2])  => [1, 2, 3]
ARRAY_DISTINCT(ARRAY['apple', 'apple', NULL, 'cherry'])  => ['apple', NULL, 'cherry']
``````

### `ARRAY_EXCEPT`¶

Since: 0.10.0
`1`
``````ARRAY_EXCEPT(array1, array2)
``````

Returns an array of all the distinct elements from an array, except for those also present in a second array.

The order of entries in the first array is preserved but duplicates are removed.

Returns `NULL` if either input is `NULL`.

Examples
```1
2```
``````ARRAY_EXCEPT(ARRAY[1, 2, 3, 1, 2], [2, 3])  => 
ARRAY_EXCEPT(ARRAY['apple', 'apple', NULL, 'cherry'], ARRAY['cherry'])  => ['apple', NULL]
``````

### `ARRAY_INTERSECT`¶

Since: 0.10.0
`1`
``````ARRAY_INTERSECT(array1, array2)
``````

Returns an array of all the distinct elements from the intersection of both input arrays.

The order of entries in the output is the same as in the first input array.

Returns `NULL` if either input array is `NULL`.

Examples
```1
2```
``````ARRAY_INTERSECT(ARRAY[1, 2, 3, 1, 2], [2, 1])  => [1, 2]
ARRAY_INTERSECT(ARRAY['apple', 'apple', NULL, 'cherry'], ARRAY['apple'])  => ['apple']
``````

### `ARRAY_JOIN`¶

Since: 0.10.0
`1`
``````ARRAY_JOIN(col1, delimiter)
``````

Creates a flat string representation of all the elements contained in an array.

The elements in the resulting string are separated by the chosen `delimiter`, which is an optional parameter. The default is the comma character, `,`.

Array elements are limited to primitive ksqlDB types only.

See ARRAY_JOIN in action

### `ARRAY_LENGTH`¶

Since: 0.8.0
`1`
``````ARRAY_LENGTH(ARRAY[1, 2, 3])
``````

Returns the number of elements in an array.

If the supplied parameter is `NULL`, the method returns `NULL`.

### `ARRAY_MAX`¶

Since: 0.10.0
`1`
``````ARRAY_MAX(['foo', 'bar', 'baz'])
``````

Returns the maximum value from an array of primitive elements.

Arrays of other arrays, arrays of maps, arrays of structs, or combinations of these types aren't supported.

If the array field is `NULL`, or contains only `NULL` values, `NULL` is returned.

Array entries are compared according to their natural sort order, which sorts the various data types as shown in the following examples.

Examples
```1
2
3```
``````ARRAY_MAX[-1, 2, NULL, 0] => 2
ARRAY_MAX[false, NULL, true] => true
ARRAY_MAX['Foo', 'Bar', NULL, 'baz'] => 'baz' -- (lower-case characters are "greater" than upper-case characters)
``````

### `ARRAY_MIN`¶

Since: 0.10.0
`1`
``````ARRAY_MIN(['foo', 'bar', 'baz'])
``````

Returns the minimum value from an array of primitive elements.

Arrays of other arrays, arrays of maps, arrays of structs, or combinations of these types aren't supported.

If the array field is `NULL`, or contains only `NULL` values, `NULL` is returned.

Array entries are compared according to their natural sort order, which sorts the various data types as shown in the following examples.

Examples
```1
2
3```
``````ARRAY_MIN[-1, 2, NULL, 0] => -1
ARRAY_MIN[false, NULL, true] => false
ARRAY_MIN['Foo', 'Bar', NULL, 'baz'] => 'Bar'
``````

### `ARRAY_REMOVE`¶

Since: 0.11.0
`1`
``````ARRAY_REMOVE(array, element)
``````

Removes all elements from `array` that are equal to `element`.

If the `array` field is `NULL`, `NULL` is returned.

Examples
```1
2
3```
``````ARRAY_REMOVE([1, 2, 3, 2, 1], 2) => [1, 3, 1]
ARRAY_REMOVE([false, NULL, true, true], false) => [NULL, true, true]
ARRAY_REMOVE(['Foo', 'Bar', NULL, 'baz'], null) => ['Foo', 'Bar', 'baz']
``````

### `ARRAY_SORT`¶

Since: 0.10.0
`1`
``````ARRAY_SORT(['foo', 'bar', 'baz'], 'ASC|DESC')
``````

Given an array of primitive elements, returns an array of the same elements sorted according to their natural sort order.

Arrays of other arrays, arrays of maps, arrays of structs, or combinations of these types aren't supported.

Any `NULL` values in the array are moved to the end.

If the array field is `NULL`, `NULL` is returned.

The optional second parameter specifies whether to sort the elements in ascending (`ASC`) or descending (`DESC`) order. If neither is specified, the default is ascending order.

Examples
```1
2
3```
``````ARRAY_SORT[-1, 2, NULL, 0] -> [-1, 0, 2, NULL]
ARRAY_SORT[false, NULL, true] -> [false, true, NULL]
ARRAY_SORT['Foo', 'Bar', NULL, 'baz'] -> ['Bar', 'Foo', 'baz', NULL]
``````

See ARRAY_SORT in action

### `ARRAY_UNION`¶

Since: 0.10.0
`1`
``````ARRAY_UNION(array1, array2)
``````

Returns an array of all the distinct elements from both input arrays, in the order they're encountered.

Returns `NULL` if either input array is `NULL`.

Examples
```1
2```
``````ARRAY_UNION(ARRAY[1, 2, 3, 1, 2], [4, 1])  => [1, 2, 3, 4]
ARRAY_UNION(ARRAY['apple', 'apple', NULL, 'cherry'], ARRAY['cherry'])  => ['apple', NULL, 'cherry']
``````

### `AS_MAP`¶

Since: 0.6.0
`1`
``````AS_MAP(keys, vals)
``````

Constructs a map from a list of keys and a list of values.

See AS_MAP in action

### `ELT`¶

Since: 0.6.0
`1`
``````ELT(n INTEGER, args VARCHAR[])
``````

Returns element `n` in the `args` list of strings, or `NULL` if `n` is less than 1 or greater than the number of arguments.

The `ELT` function is 1-indexed.

`ELT` is the complement to the `FIELD` function.

### `FIELD`¶

Since: 0.6.0
`1`
``````FIELD(str VARCHAR, args VARCHAR[])
``````

Returns the 1-indexed position of `str` in `args`, or 0 if not found.

If `str` is `NULL`, the return value is 0, because `NULL` isn't considered to be equal to any value.

`FIELD` is the complement to the `ELT` function.

### `JSON_ARRAY_CONTAINS`¶

Since: 0.6.0
`1`
``````JSON_ARRAY_CONTAINS('[1, 2, 3]', 3)
``````

Given a `STRING` containing a JSON array, checks if a search value is contained in the array.

Returns `false` if the first parameter doesn't contain a JSON array.

### `MAP`¶

Since: 0.7.0
`1`
``````MAP(key VARCHAR := value, …)
``````

Constructs a map from specific key-value tuples.

All values must be coercible to a common SQL type.

### `MAP_KEYS`¶

Since: 0.10.0
`1`
``````MAP_KEYS(a_map)
``````

Returns an array that contains all keys from the specified map.

Returns `NULL` if the input map is `NULL`.

Example
`1`
``````map_keys( map('apple' := 10, 'banana' := 20) )  => ['apple', 'banana']
``````

### `MAP_VALUES`¶

Since: 0.10.0
`1`
``````MAP_VALUES(a_map)
``````

Returns an array that contains all values from the specified map.

Returns `NULL` if the input map is `NULL`.

Example
`1`
``````map_values( map('apple' := 10, 'banana' := 20) )  => [10, 20]
``````

### `MAP_UNION`¶

Since: 0.10.0
`1`
``````MAP_UNION(map1, map2)
``````

Returns a new map containing the union of all entries from both input maps.

If a key is present in both input maps, the corresponding value from map2 is returned.

Returns `NULL` if all input maps are `NULL`.

Examples
```1
2```
``````MAP_UNION( MAP('apple' := 10, 'banana' := 20), MAP('cherry' := 99) )  => ['apple': 10, 'banana': 20, 'cherry': 99]
MAP_UNION( MAP('apple' := 10, 'banana' := 20), MAP('apple' := 50) )  => ['apple': 50, 'banana': 20]
``````

### `SLICE`¶

Since: 0.6.0
`1`
``````SLICE(col1, from, to)
``````

Slices a list based on the supplied indices.

The indices start at 1 and include both endpoints.

## Invocation Functions¶

Apply lambda functions to collections.

### `FILTER`¶

Since: 0.17.0
```1
2```
``````FILTER(array, x => …)
FILTER(map, (k,v) => …)
``````

Filters a collection with a lambda function.

If the collection is an array, the lambda function must have one input argument.

If the collection is a map, the lambda function must have two input arguments.

### `REDUCE`¶

Since: 0.17.0
```1
2```
``````REDUCE(array, state, (s, x) => …)
REDUCE(map, state, (s, k, v) => …)
``````

Reduces a collection starting from an initial state.

If the collection is an array, the lambda function must have two input arguments.

If the collection is a map, the lambda function must have three input arguments.

If the state is `NULL`, the result is `NULL`.

### `TRANSFORM`¶

Since: 0.17.0
```1
2```
``````TRANSFORM(array, x => …)
TRANSFORM(map, (k,v) => …, (k,v) => …)
``````

Transforms a collection by using a lambda function.

If the collection is an array, the lambda function must have one input argument.

If the collection is a map, two lambda functions must be provided, and both lambdas must have two arguments: a map entry key and a map entry value.

## Strings¶

### `CHR`¶

Since: 0.10.0
`1`
``````CHR(decimal_code | utf_string)
``````

Returns a single-character string representing the Unicode code-point described by the input.

The input parameter can be either a decimal character code or a string representation of a UTF code.

Returns `NULL` if the input is `NULL` or doesn't represent a valid code-point.

Commonly used to insert control characters such as `Tab` (9), `Line Feed` (10), or `Carriage Return` (13) into strings.

Examples
```1
2
3
4```
``````CHR(75)        => 'K'
CHR('\u004b')  => 'K'
CHR(22909)     => '好'
CHR('\u597d')  => '好'
``````

### `CONCAT`¶

Since: 0.1.0
```1
2```
``````CONCAT(col1, col2, 'hello', …, col-n)
CONCAT(bytes1, bytes2, …, bytes-n)
``````

Concatenates two or more string or bytes expressions.

Any inputs which evaluate to `NULL` are replaced with an empty string or bytes in the output.

See CONCAT in action

### `CONCAT_WS`¶

Since: 0.10.0
`1`
``````CONCAT_WS(separator, expr1, expr2, …)
``````

Concatenates two or more string or bytes expressions, inserting a separator string or bytes between each.

If the separator is `NULL`, this function returns `NULL`.

Any expressions which evaluate to `NULL` are skipped.

Example
`1`
``````CONCAT_WS(', ', 'apple', 'banana', NULL, 'date')  ->  'apple, banana, date'
``````

### `ENCODE`¶

Since: 0.10.0
`1`
``````ENCODE(col1, input_encoding, output_encoding)
``````

Given a STRING that is encoded as `input_encoding`, encode it using the `output_encoding`.

The accepted input and output encodings are:

• `hex`
• `utf8`
• `ascii`
• `base64`

Throws an exception if the provided encodings are not supported.

The following example encodes a `hex` representation of a string to a `utf8` representation.

Example
`1`
``````ENCODE(string, 'hex', 'utf8')
``````

### `EXTRACTJSONFIELD`¶

Since: 0.11.0
`1`
``````EXTRACTJSONFIELD(message, '\$.log.cloud')
``````

Given a `STRING` that contains JSON data, extracts the value at the specified JSONPath.

For example, given a STRING containing the following JSON:

 ```1 2 3 4 5 6 7``` ``````{ "log": { "cloud": "gcp836Csd", "app": "ksProcessor", "instance": 4 } } ``````

`EXTRACTJSONFIELD(message, '\$.log.cloud')` returns the STRING `gcp836Csd`.

If the requested JSONPath does not exist, the function returns `NULL`.

The result of `EXTRACTJSONFIELD` is always a `STRING`. Use `CAST` to convert the result to another type.

For example, `CAST(EXTRACTJSONFIELD(message, '\$.log.instance') AS INT)` extracts the instance number from the previous JSON object as a `INT`.

The return type of `EXTRACTJSONFIELD` is `STRING`, so JSONPaths that select multiple elements, like those containing wildcards, aren't supported.

Note

`EXTRACTJSONFIELD` is useful for extracting data from JSON when either the schema of the JSON data isn't static or the JSON data is embedded in a row that's encoded using a different format, for example, a JSON field within an Avro-encoded message.

If the whole row is encoded as JSON with a known schema or structure, use the `JSON` format and define the structure as the source's columns.

For example, a stream of JSON objects similar to the previous example could be defined using a statement similar to the following:

 ```1 2``` ``````CREATE STREAM LOGS (LOG STRUCT, …) WITH (VALUE_FORMAT='JSON', …) ``````

### `FROM_BYTES`¶

Since: 0.21.0
`1`
``````FROM_BYTES(bytes, encoding)
``````

Converts a `BYTES` column to a `STRING` in the specified encoding type.

The following list shows the supported encoding types.

• `hex`
• `utf8`
• `ascii`
• `base64`

### `IS_JSON_STRING`¶

Since: 0.24.0
`1`
``````IS_JSON_STRING(json_string) => Boolean
``````

Returns `true` if `json_string` can be parsed as a valid JSON value; otherwise, `false` .

Examples
```1
2
3
4
5
6
7
8```
``````IS_JSON_STRING('[1, 2, 3]') => true
IS_JSON_STRING('{}') => true
IS_JSON_STRING('1') => true
IS_JSON_STRING('\"abc\"') => true
IS_JSON_STRING('null') => true
IS_JSON_STRING('') => false
IS_JSON_STRING('abc') => false
IS_JSON_STRING(NULL) => false
``````

### `JSON_ARRAY_LENGTH`¶

Since: 0.24.0
`1`
``````JSON_ARRAY_LENGTH(json_string) => Integer
``````

Parses `json_string` as a JSON value and returns the length of the top-level array.

Returns `NULL` if the string can't be interpreted as a JSON array, for example, when the string is `NULL` or it doesn't contain valid JSON, or the JSON value is not an array.

Examples
```1
2
3
4
5
6
7```
``````JSON_ARRAY_LENGTH('[1, 2, 3]') => 3
JSON_ARRAY_LENGTH('[1, [1, ], 3]') =>  3
JSON_ARRAY_LENGTH('[]') => 0
JSON_ARRAY_LENGTH('{}') => NULL
JSON_ARRAY_LENGTH('123') => NULL
JSON_ARRAY_LENGTH(NULL) => NULL
JSON_ARRAY_LENGTH('abc') => returns NULL and logs an "Invalid JSON format" exception in server log
``````

### `JSON_CONCAT`¶

Since: 0.24.0
`1`
``````JSON_CONCAT(json_string1, json_string2, ...) => String
``````

Given N strings, parses them as JSON values and returns a string representing their concatenation.

Concatenation rules are identical to PostgreSQL's || operator:

• If all strings deserialize into JSON objects, return an object with a union of the input keys. If there are duplicate objects, take values from the last object.
• If all strings deserialize into JSON arrays, return the result of array concatenation.
• If at least one of the deserialized values is not an object, convert non-array inputs to a single-element array and return the result of array concatenation.
• If at least one of the input strings is `NULL` or can't be deserialized as JSON, return `NULL`.

Similar to PostgreSQL's `||` operator, this function merges only top-level object keys or arrays.

Examples:

Examples
``` 1
2
3
4
5
6
7
8
9
10
11
12```
``````JSON_CONCAT('{\"a\": 1}', '{\"b\": 2}') => '{"a":1,"b":2}'
JSON_CONCAT('{\"a\": {\"5\": 6}}', '{\"a\": {\"3\": 4}}') => '{"a":{"3":4}}'
JSON_CONCAT('{}', '{}') => '{}'
JSON_CONCAT('[1, 2]', '[3, 4]') => '[1,2,3,4]'
JSON_CONCAT('[1, ]', '[[], [[]]]') => '[ 1, , [], [[]] ]'
JSON_CONCAT('null', 'null') => '[null, null]'
JSON_CONCAT('[1, 2]', '{\"a\": 1}') => '[1,2,{"a":1}]'
JSON_CONCAT('[1, 2]', '3') => '[1, 2, 3]'
JSON_CONCAT('1', '2') => '[1, 2]'
JSON_CONCAT('[]', '[]') => '[]'
JSON_CONCAT('abc', '') => NULL
JSON_CONCAT(NULL, '') => NULL
``````

### `JSON_KEYS`¶

Since: 0.24.0
`1`
``````JSON_KEYS(json_string) => Array<String>
``````

Parses `json_string` as a JSON object and returns an array of strings representing the top-level keys.

Returns `NULL` if the string can't be interpreted as a JSON object, for example, when the string is `NULL` or it does not contain valid JSON, or the JSON value is not an object.

Examples
```1
2
3
4
5
6```
``````JSON_KEYS('{\"a\": \"abc\", \"b\": { \"c\": \"a\" }, \"d\": 1}') => ['a', 'b', 'd']
JSON_KEYS('{}') => []
JSON_KEYS('[]') => NULL
JSON_KEYS('123') => NULL
JSON_KEYS(NULL) => NULL
JSON_KEYS('') => NULL
``````

### `JSON_RECORDS`¶

Since: 0.24.0
`1`
``````JSON_RECORDS(json_string) => Map<String, String>
``````

Parses `json_string` as a JSON object and returns a map representing the top-level keys and values.

Returns `NULL` if the string can't be interpreted as a JSON object, for example, when the string is `NULL` or it does not contain valid JSON, or the JSON value is not an object.

Examples
```1
2
3
4
5
6```
``````JSON_RECORDS('{\"a\": \"abc\", \"b\": { \"c\": \"a\" }, \"d\": 1}') => {d=1, a="abc", b={"c":"a"}}
JSON_RECORDS('{}') => {}
JSON_RECORDS('[]') => NULL
JSON_RECORDS('123') => NULL
JSON_RECORDS(NULL) => NULL
JSON_RECORDS('abc') => NULL
``````

### `TO_JSON_STRING`¶

Since: 0.24.0
`1`
``````TO_JSON_STRING(val) => String
``````

Given any ksqlDB type, returns the equivalent JSON string.

Primitives types
```1
2
3
4
5
6
7
8```
``````TO_JSON_STRING(1) => '1'
TO_JSON_STRING(15.3) => '15.3'
TO_JSON_STRING('abc') => '"abc"'
TO_JSON_STRING(true) => 'true'
TO_JSON_STRING(PARSE_DATE('2021-10-11', 'yyyy-MM-dd')) => '"2021-10-11"'
TO_JSON_STRING(PARSE_TIME('13:25', 'HH:mm')) => '"13:25"'
TO_JSON_STRING(PARSE_TIMESTAMP('2021-06-31 12:18:39.446', 'yyyy-MM-dd HH:mm:ss.SSS')) => '"2021-06-30T12:18:39.446"'
TO_JSON_STRING(NULL) => 'null'
``````
Compound types
```1
2
3
4```
``````TO_JSON_STRING(Array[1, 2, 3]) => '[1, 2, 3]'
TO_JSON_STRING(Struct(id := 1, name := 'A')) => '{"ID":1,"NAME":"A"}'
TO_JSON_STRING(Map('c' := 2, 'd' := 4)) => '{"c": 2, "d": 4}'
TO_JSON_STRING(Array[Struct(json_key := 1, json_value := Map('c' := 2, 'd' := 3))]) => '[{"JSON_KEY": 1, "JSON_VALUE": {"c": 2, "d": 3}}]'
``````

### `INITCAP`¶

Since: 0.6.0
`1`
``````INITCAP(col1)
``````

Capitalizes the first letter in each word and converts all other letters to lowercase.

Words are delimited by whitespace.

### `INSTR`¶

Since: 0.10.0
`1`
``````INSTR(string, substring, [position], [occurrence])
``````

Returns the position of `substring` in `string`.

The first character is at position 1.

If `position` is provided, search starts from the specified position.

A negative value for `position` causes the search to work from the end to the start of `string`.

If `occurrence` is provided, the position of the n-th occurrence is returned.

If `substring` is not found, the return value is 0.

Examples
```1
2
3
4
5
6```
``````INSTR('CORPORATE FLOOR', 'OR') -> 2
INSTR('CORPORATE FLOOR', 'OR', 3) -> 5
INSTR('CORPORATE FLOOR', 'OR', 3, 2) -> 14
INSTR('CORPORATE FLOOR', 'OR', -3) -> 5
INSTR('CORPORATE FLOOR', 'OR', -3, 2) -> 2b
INSTR('CORPORATE FLOOR', 'MISSING') -> 0
``````

### `LCASE`¶

Since: 0.1.0
`1`
``````LCASE(col1)
``````

Converts a string to lowercase.

### `LEN`¶

Since: 0.1.0
```1
2```
``````LEN(string)
LEN(bytes)
``````

Returns the length of a `STRING` or the number of bytes in a `BYTES` value.

### `LPAD`¶

Since: 0.10.0
`1`
``````LPAD(input, length, padding)
``````

Pads the input string or bytes, beginning from the left, with the specified padding of the same type, until the target length is reached.

If the input is longer than `length`, it is truncated.

If the padding string or byte array is empty or `NULL`, or the target length is negative, `NULL` is returned.

Examples
```1
2
3
4```
``````LPAD('Foo', 7, 'Bar')  =>  'BarBFoo'
``````

### `MASK`¶

Since: 0.6.0
`1`
``````MASK(col1, 'X', 'x', 'n', '-')
``````

Convert a string to a masked or obfuscated version of itself.

The optional arguments following the input string to be masked are the characters to be substituted for upper-case, lower-case, numeric, and other characters of the input, respectively.

If the mask characters are omitted, the default values are applied, as shown in the following example.

 `1` ``````MASK("My Test \$123") => "Xx-Xxxx--nnn" ``````

Set a given mask character to `NULL` to prevent any masking of that character type.

 `1` ``````MASK("My Test \$123", '*', NULL, '1', NULL) => "*y *est \$111" ``````

### `MASK_KEEP_LEFT`¶

Since: 0.6.0
`1`
``````MASK_KEEP_LEFT(col1, numChars, 'X', 'x', 'n', '-')
``````

Similar to the `MASK` function, except that the first or left-most `numChars` characters aren't masked in any way.

Example
`1`
``````MASK_KEEP_LEFT("My Test \$123", 4) => "My Txxx--nnn"
``````

### `MASK_KEEP_RIGHT`¶

Since: 0.6.0
`1`
``````MASK_KEEP_RIGHT(col1, numChars, 'X', 'x', 'n', '-')
``````

Similar to the `MASK` function, except that the last or right-most `numChars` characters aren't masked in any way.

Example
`1`
``````MASK_KEEP_RIGHT("My Test \$123", 4) => "Xx-Xxxx-\$123"
``````

### `MASK_LEFT`¶

Since: 0.6.0
`1`
``````MASK_LEFT(col1, numChars, 'X', 'x', 'n', '-')
``````

Similar to the `MASK` function, except that only the first or left-most `numChars` characters have any masking applied to them.

Example
`1`
``````MASK_LEFT("My Test \$123", 4) => "Xx-Xest \$123"
``````

### `MASK_RIGHT`¶

Since: 0.6.0
`1`
``````MASK_RIGHT(col1, numChars, 'X', 'x', 'n', '-')
``````

Similar to the `MASK` function, except that only the last or right-most `numChars` characters have any masking applied to them.

Example
`1`
``````MASK_RIGHT("My Test \$123", 4) => "My Test -nnn"
``````

### `REPLACE`¶

Since: 0.6.0
`1`
``````REPLACE(col1, 'foo', 'bar')
``````

Replaces all instances of a substring in a string with a new string.

See REPLACE in action

### `REGEXP_EXTRACT`¶

Since: 0.8.0
```1
2```
``````REGEXP_EXTRACT('.*', col1)
REGEXP_EXTRACT('(([AEIOU]).)', col1, 2)
``````

Extracts the first substring matched by the regular expression pattern from the input.

You can specify a capturing group number to return that specific group. If a number isn't specified, the entire substring is returned by default.

Example
`1`
``````REGEXP_EXTRACT("(.*) (.*)", 'hello there', 2) => "there"
``````

### `REGEXP_EXTRACT_ALL`¶

Since: 0.10.0
```1
2```
``````REGEXP_EXTRACT_ALL('.*', col1)
REGEXP_EXTRACT_ALL('(([AEIOU]).)', col1, 2)
``````

Extracts all subtrings matched by the regular expression pattern from the input.

You can specify a capturing group number to return that specific group. If a number isn't specified, the entire substring is returned by default.

Example
`1`
``````REGEXP_EXTRACT("(\\w+) (\\w+)", "hello there nice day", 2) => ["there", "day"]
``````

### `REGEXP_REPLACE`¶

Since: 0.10.0
`1`
``````REGEXP_REPLACE(col1, 'a.b+', 'bar')
``````

Replaces all matches of a regular expression in an input string with a new string.

If either the input string, the regular expression, or the new string is `NULL`, the result is `NULL`.

### `REGEXP_SPLIT_TO_ARRAY`¶

Since: 0.10.0
`1`
``````REGEXP_SPLIT_TO_ARRAY(col1, 'a.b+')
``````

Splits a string into an array of substrings based on a regular expression.

If there is no match, the original string is returned as the only element in the array.

If the regular expression is empty, all characters in the string are split.

If either the string or the regular expression is `NULL`, a `NULL` value is returned.

If the regular expression is found at the beginning or end of the string, or there are contiguous matches, an empty element is added to the array.

### `RPAD`¶

Since: 0.10.0
`1`
``````RPAD(input, length, padding)
``````

Pads the input string or bytes, starting from the end, with the specified padding of the same type, until the target length is reached.

If the input is longer than the specified target length, it is truncated.

If the padding string or byte array is empty or `NULL`, or the target length is negative, `NULL` is returned.

Examples
```1
2
3```
``````RPAD('Foo', 7, 'Bar')  =>  'FooBarB'
``````

### `SPLIT`¶

Since: 0.6.0
`1`
``````SPLIT(col1, delimiter)
``````

Splits a string into an array of substrings, or bytes into an array of subarrays, based on a delimiter.

If the delimiter isn't found, the original string or byte array is returned as the only element in the array.

If the delimiter is empty, every character in the string or byte in the array is split.

If the delimiter is found at the beginning or end of the string or bytes, or there are contiguous delimiters, an empty space is added to the array.

Returns `NULL` if either parameter is `NULL`.

See SPLIT in action

### `SPLIT_TO_MAP`¶

Since: 0.10.0
`1`
``````SPLIT_TO_MAP(input, entryDelimiter, kvDelimiter)
``````

Splits a string into key-value pairs and creates a map from them.

The `entryDelimiter` splits the string into key-value pairs which are then split by `kvDelimiter`.

If the same key is present multiple times in the input, the latest value for the key is returned.

Returns `NULL` if the input text is `NULL`.

Returns `NULL` if either of the delimiters is `NULL` or an empty string.

Example
`1`
``````SPLIT_TO_MAP('apple':='green'/'cherry':='red', '/', ':=')  => { 'apple':'green', 'cherry':'red'}
``````

### `SUBSTRING`¶

Since: 0.1.0
```1
2```
``````SUBSTRING(str, pos, [len])
SUBSTRING(bytes, pos, [len])
``````

Returns the portion of `str` or `bytes` that starts at `pos` and has length `len`, or continues to the end of the string or bytes.

The first character or byte is at position 1.

Example
`1`
``````SUBSTRING("stream", 1, 4)  => "stre"
``````

### `TO_BYTES`¶

Since: 0.21.0
`1`
``````TO_BYTES(string, encoding)
``````

Converts a `STRING` column in the specified encoding type to a `BYTES` column.

The following list shows the supported encoding types.

• `hex`
• `utf8`
• `ascii`
• `base64`

### `TRIM`¶

Since: 0.1.0
`1`
``````TRIM(col1)
``````

Removes the spaces from the beginning and end of a string.

### `UCASE`¶

Since: 0.1.0
`1`
``````UCASE(col1)
``````

Converts a string to uppercase.

See UCASE in action

### `UUID`¶

Since: 0.10.0
`1`
``````UUID()
``````
Creates a Universally Unique Identifier (UUID) generated according to RFC 4122.

A call to UUID() returns a value conforming to UUID version 4, sometimes called "random UUID", as described in RFC 4122.

The value is a 128-bit number represented as a string of five hexadecimal numbers, aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee, for example, `237e9877-e79b-12d4-a765-321741963000`.

## Bytes¶

### `BIGINT_FROM_BYTES`¶

Since: 0.23.1
`1`
``````BIGINT_FROM_BYTES(col1, [byteOrder])
``````

Converts a `BYTES` value to a `BIGINT` value according to the specified byte order.

`BYTES` must be 8 bytes long, or a `NULL` value is returned.

Byte order values must be `BIG_ENDIAN` or `LITTLE_ENDIAN`. If omitted, `BIG_ENDIAN` is used.

A `NULL` value is returned if an invalid byte order value is provided.

Example, where `b` is a `BYTES` value represented as a base64 string `AAAAASoF8gA=`:

 `1` ``````BIGINT_FROM_BYTES(b, 'BIG_ENDIAN') => 5000000000 ``````

### `DOUBLE_FROM_BYTES`¶

Since: 0.23.1
`1`
``````DOUBLE_FROM_BYTES(col1, [byteOrder])
``````

Converts a `BYTES` value to a `DOUBLE` value according to the specified byte order.

`BYTES` must be 8 bytes long, or a `NULL` value is returned.

Byte order values must be `BIG_ENDIAN` or `LITTLE_ENDIAN`. If omitted, `BIG_ENDIAN` is used.

A `NULL` value is returned if an invalid byte order value is provided.

Example, where `b` is a `BYTES` value represented as a base64 string `QICm/ZvJ9YI=`:

 `1` ``````DOUBLE_FROM_BYTES(b, 'BIG_ENDIAN') => 532.8738323 ``````

### `INT_FROM_BYTES`¶

Since: 0.23.1
`1`
``````INT_FROM_BYTES(col1, [byteOrder])
``````

Converts a `BYTES` value to an `INT` value according to the specified byte order.

`BYTES` must be 4 bytes long, or a `NULL` value is returned.

Byte order values must be `BIG_ENDIAN` or `LITTLE_ENDIAN`. If omitted, `BIG_ENDIAN` is used.

A `NULL` value is returned if an invalid byte order value is provided.

Example, where `b_big` is a `BYTES` value represented as a base64 string `AAAH5Q==`:

 `1` ``````INT_FROM_BYTES(b, 'BIG_ENDIAN') -> 2021 ``````

### `TO_BYTES`¶

Since: 0.21.0
`1`
``````TO_BYTES(col1, encoding)
``````

Converts a `STRING` value in the specified encoding to `BYTES`.

The following list shows the supported encoding types.

• `hex`
• `utf8`
• `ascii`
• `base64`

## Nulls¶

### `COALESCE`¶

Since: 0.9.0
`1`
``````COALESCE(a, b, c, d)
``````

Returns the first parameter that is not `NULL`. All parameters must be of the same type.

If the parameter is a complex type, for example, `ARRAY` or `STRUCT`, the contents of the complex type are not inspected. The behaviour is the same: the first `NOT NULL` element is returned.

### `IFNULL`¶

Since: 0.9.0
`1`
``````IFNULL(expression, altValue)
``````

If `expression` is `NULL`, returns `altValue`; otherwise, returns `expression`.

If `expression` evaluates to a complex type, for example, `ARRAY` or `STRUCT`, the contents of the complex type are not inspected.

### `NULLIF`¶

Since: 0.19.0
`1`
``````NULLIF(expression1, expression2)
``````

Returns `NULL` if `expression1` is equal to `expression2`; otherwise, returns `expression1`.

If `expression` evaluates to a complex type, for example, `ARRAY` or `STRUCT`, the contents of the complex type are not inspected.

## Date and time¶

### `CONVERT_TZ`¶

Since: 0.17.0
`1`
``````CONVERT_TZ(col1, 'from_timezone', 'to_timezone')
``````

Converts a `TIMESTAMP` value from `from_timezone` to `to_timezone`.

The `from_timezone` and `to_timezone` parameters are `java.util.TimeZone` ID formats, for example:

• "UTC"
• "America/Los_Angeles"
• "PDT"
• "Europe/London"

### `DATEADD`¶

Since: 0.20.0
`1`
``````DATEADD(unit, interval, col0)
``````

Adds an interval to a date.

Intervals are defined by an integer value and a supported time unit.

### `DATESUB`¶

Since: 0.20.0
`1`
``````DATESUB(unit, interval, col0)
``````

Subtracts an interval from a date.

Intervals are defined by an integer value and a supported time unit.

### `FORMAT_DATE`¶

Since: 0.20.0
`1`
``````FORMAT_DATE(date, 'yyyy-MM-dd')
``````

Converts a `DATE` value into a string that represents the date in the specified format.

You can escape single-quote characters in the timestamp format by using two successive single quotes, `''`, for example: `'yyyy-MM-dd''T'''`.

### `FORMAT_TIME`¶

Since: 0.20.0
`1`
``````FORMAT_TIME(time, 'HH:mm:ss.SSS')
``````

Converts a `TIME` value into the string representation of the time in the given format.

You can escape single-quote characters in the time format by using two successive single quotes, `''`, for example: `'''T''HH:mm:ssX'`.

### `FORMAT_TIMESTAMP`¶

Since: 0.17.0
`1`
``````FORMAT_TIMESTAMP(timestamp, 'yyyy-MM-dd HH:mm:ss.SSS' [, TIMEZONE])
``````

Converts a `TIMESTAMP` value into the string representation of the timestamp in the specified format.

You can escape single-quote characters in the timestamp format by using two successive single quotes, `''`, for example: `'yyyy-MM-dd''T''HH:mm:ssX'`.

The optional `TIMEZONE` parameter is a `java.util.TimeZone` ID format, for example:

• "UTC"
• "America/Los_Angeles"
• "PDT"
• "Europe/London"

Note

To use the `FORMAT_TIMESTAMP` function with a BIGINT millisecond timestamp parameter, convert the millisecond value to a `TIMESTAMP` by using the `FROM_UNIXTIME` function, for example:

 `1` ``````FORMAT_TIMESTAMP(FROM_UNIXTIME(unix_timestamp)) ``````

See FORMAT_TIMESTAMP in action

### `FROM_DAYS`¶

Since: 0.20.0
`1`
``````FROM_DAYS(days)
``````

Converts an `INT` number of days since epoch to a `DATE` value.

### `FROM_UNIXTIME`¶

Since: 0.17.0
`1`
``````FROM_UNIXTIME(milliseconds)
``````

Converts a `BIGINT` millisecond timestamp value into a `TIMESTAMP` value.

See FROM_UNIXTIME in action

### `PARSE_DATE`¶

Since: 0.20.0
`1`
``````PARSE_DATE(col1, 'yyyy-MM-dd')
``````

Converts a string representation of a date in the specified format into a `DATE` value.

You can escape single-quote characters in the timestamp format by using two successive single quotes, `''`, for example: `'yyyy-MM-dd''T'''`.

### `PARSE_TIME`¶

Since: 0.20.0
`1`
``````PARSE_TIME(col1, 'HH:mm:ss.SSS')
``````

Converts a string value in the specified format into a `TIME` value.

You can escape single-quote characters in the time format by using successive single quotes, `''`, for example: `'''T''HH:mm:ssX'`.

### `PARSE_TIMESTAMP`¶

Since: 0.17.0
`1`
``````PARSE_TIMESTAMP(col1, 'yyyy-MM-dd HH:mm:ss.SSS' [, TIMEZONE])
``````

Converts a string value in the given format into the `TIMESTAMP` value.

You can escape single-quote characters in the timestamp format by using successive single quotes, `''`, for example: `'yyyy-MM-dd''T''HH:mm:ssX'`.

The optional `TIMEZONE` parameter is a `java.util.TimeZone` ID format, for example:

• "UTC"
• "America/Los_Angeles"
• "PDT"
• "Europe/London"

The timestamp format permits up to 9 digits in the millisecond field, for example, `yyyy-MM-dd HH:mm:ss.SSSSSSSSS`. If you provide more than 9 digits, the function fails to parse the timestamp.

### `TIMEADD`¶

Since: 0.20.0
`1`
``````TIMEADD(unit, interval, COL0)
``````

Adds an interval to a `TIME`.

Intervals are defined by an integer value and a supported time unit.

### `TIMESUB`¶

Since: 0.20.0
`1`
``````TIMESUB(unit, interval, COL0)
``````

Subtracts an interval from a `TIME`.

Intervals are defined by an integer value and a supported time unit.

### `TIMESTAMPADD`¶

Since: 0.17.0
`1`
``````TIMESTAMPADD(unit, interval, COL0)
``````

Adds an interval to a `TIMESTAMP`.

Intervals are defined by an integer value and a supported time unit.

### `TIMESTAMPSUB`¶

Since: 0.17.0
`1`
``````TIMESTAMPSUB(unit, interval, COL0)
``````

Subtracts an interval from a `TIMESTAMP`.

Intervals are defined by an integer value and a supported time unit.

### `UNIX_DATE`¶

Since: 0.6.0
`1`
``````UNIX_DATE([date])
``````

If `UNIX_DATE` is called with the date parameter, the function returns the `DATE` value as an `INTEGER` value representing the number of days since `1970-01-01`.

If the `date` parameter is not provided, the function returns an integer representing days since `1970-01-01`.

Important

The returned integer may differ depending on the local time of different ksqlDB Server instances.

### `UNIX_TIMESTAMP`¶

Since: 0.6.0
`1`
``````UNIX_TIMESTAMP([timestamp])
``````

If `UNIX_TIMESTAMP` is called with the timestamp parameter, the function returns the `TIMESTAMP` value as a `BIGINT` value representing the number of milliseconds since `1970-01-01T00:00:00 UTC`.

If the `timestamp` parameter is not provided, the function returns the current UNIX timestamp in milliseconds, represented as a `BIGINT`.

Important

The returned `BIGINT` may differ depending on the local time of different ksqlDB Server instances.

## URLs¶

All ksqlDB URL functions assume URI syntax defined in RFC 39386. For more information on the structure of a URI, including definitions of the various components, see Section 3 of the RFC.

For encoding and decoding, ksqlDB uses the `application/x-www-form-urlencoded` convention.

### `URL_DECODE_PARAM`¶

Since: 0.6.0
`1`
``````URL_DECODE_PARAM(col1)
``````

Unescapes the `URL-param-encoded`_ value in `col1`.

This is the inverse of the `URL_ENCODE_PARAM` function.

Example
`1`
``````URL_DECODE_PARAM("url%20encoded") => "url encoded"
``````

### `URL_ENCODE_PARAM`¶

Since: 0.6.0
`1`
``````URL_ENCODE_PARAM(col1)
``````

Escapes the value of `col1` such that it can safely be used in URL query parameters.

Note

`URL_ENCODE_PARAM` is not the same as encoding a value for use in the path portion of a URL.

Example
`1`
``````URL_ENCODE_PARAM("url encoded") => "url%20encoded"
``````

### `URL_EXTRACT_FRAGMENT`¶

Since: 0.6.0
`1`
``````URL_EXTRACT_FRAGMENT(url)
``````

Extracts the fragment portion of the specified value.

Returns `NULL` if `url` is not a valid URL or if the fragment doesn't exist.

All encoded values are decoded.

Examples
```1
2```
``````URL_EXTRACT_FRAGMENT("http://test.com#frag") => "frag"
URL_EXTRACT_FRAGMENT("http://test.com#frag%20space") => "frag space"
``````

### `URL_EXTRACT_HOST`¶

Since: 0.6.0
`1`
``````URL_EXTRACT_HOST(url)
``````

Extracts the host-name portion of the specified value.

Returns `NULL` if `url` is not a valid URI according to RFC-2396.

Example
`1`
``````URL_EXTRACT_HOST("http://test.com:8080/path") => "test.com"
``````

### `URL_EXTRACT_PARAMETER`¶

Since: 0.6.0
`1`
``````URL_EXTRACT_PARAMETER(url, parameter_name)
``````

Extracts the value of the requested parameter from the query-string of `url`.

Returns `NULL` if the parameter is not present, has no value specified for it in the query string, or `url` is not a valid URI.

The function encodes the parameter and decodes the output.

To get all parameter values from a URL as a single string, use `URL_EXTRACT_QUERY.`

Examples
```1
2```
``````URL_EXTRACT_PARAMETER("http://test.com?a%20b=c%20d", "a b") => "c d"
URL_EXTRACT_PARAMETER("http://test.com?a=foo&b=bar", "b") => "bar"
``````

### `URL_EXTRACT_PATH`¶

Since: 0.6.0
`1`
``````URL_EXTRACT_PATH(url)
``````

Extracts the path from `url`.

Returns `NULL` if `url` is not a valid URI but returns an empty string if the path is empty.

Example
`1`
``````URL_EXTRACT_PATH("http://test.com/path/to#a") => "path/to"
``````

### `URL_EXTRACT_PORT`¶

Since: 0.6.0
`1`
``````URL_EXTRACT_PORT(url)
``````

Extracts the port number from `url`.

Returns `NULL` if `url` is not a valid URI or does not contain an explicit port number.

Example
`1`
``````URL_EXTRACT_PORT("http://localhost:8080/path") => "8080"
``````

### `URL_EXTRACT_PROTOCOL`¶

Since: 0.6.0
`1`
``````URL_EXTRACT_PROTOCOL(url)
``````

Extracts the protocol from `url`.

Returns `NULL` if `url` is an invalid URI or has no protocol.

Example
`1`
``````URL_EXTRACT_PROTOCOL("http://test.com?a=foo&b=bar") => "http"
``````

### `URL_EXTRACT_QUERY`¶

Since: 0.6.0
`1`
``````URL_EXTRACT_QUERY(url)
``````

Extracts the decoded query-string portion of `url`.

Returns `NULL` if no query-string is present or `url` is not a valid URI.

Example
`1`
``````URL_EXTRACT_QUERY("http://test.com?a=foo%20bar&b=baz") => "a=foo bar&b=baz"
``````

## Deprecated¶

### `DATETOSTRING`¶

Since: 0.7.1

Deprecated since 0.20.0 (use FORMAT_DATE)

 `1` ``````DATETOSTRING(START_DATE, 'yyyy-MM-dd') ``````

Converts an integer representation of a date into a string representing the date in the given format. Single quotes in the timestamp format can be escaped with two successive single quotes, `''`, for example: `'yyyy-MM-dd''T'''`. The integer represents days since epoch matching the encoding used by Connect dates.

### `STRINGTODATE`¶

Since: 0.7.1

Deprecated since 0.20.0 (use PARSE_DATE)

 `1` ``````STRINGTODATE(col1, 'yyyy-MM-dd') ``````

Converts a string representation of a date in the given format into an integer representing days since epoch. Single quotes in the timestamp format can be escaped with two successive single quotes, `''`, for example: `'yyyy-MM-dd''T'''`.

### `STRINGTOTIMESTAMP`¶

Since: 0.7.1

Deprecated since 0.17.0 (use PARSE_TIMESTAMP)

 `1` ``````STRINGTOTIMESTAMP(col1, 'yyyy-MM-dd HH:mm:ss.SSS' [, TIMEZONE]) ``````

Converts a string value in the given format into the BIGINT value
that represents the millisecond timestamp. Single quotes in the timestamp format can be escaped with two successive single quotes, `''`, for example: `'yyyy-MM-dd''T''HH:mm:ssX'`.

TIMEZONE is an optional parameter and it is a `java.util.TimeZone` ID format, for example: "UTC", "America/Los_Angeles", "PDT", "Europe/London". For more information on timestamp formats, see DateTimeFormatter.

### `TIMESTAMPTOSTRING`¶

Since: 0.7.1

Deprecated since 0.17.0 (use FORMAT_TIMESTAMP)

 `1` ``````TIMESTAMPTOSTRING(ROWTIME, 'yyyy-MM-dd HH:mm:ss.SSS' [, TIMEZONE]) ``````

Converts a BIGINT millisecond timestamp value into the string representation of the timestamp in the given format. Single quotes in the timestamp format can be escaped with two successive single quotes, `''`, for example: `'yyyy-MM-dd''T''HH:mm:ssX'`.

TIMEZONE is an optional parameter, and it is a `java.util.TimeZone` ID format, for example, "UTC", "America/Los_Angeles", "PDT", or "Europe/London". For more information on timestamp formats, see DateTimeFormatter.

Note

To use the `FORMAT_TIMESTAMP` function with a BIGINT millisecond timestamp parameter, convert the millisecond value to a `TIMESTAMP` by using the `FROM_UNIXTIME` function, for example:

 `1` ``````FORMAT_TIMESTAMP(FROM_UNIXTIME(unix_timestamp)) ``````

Last update: 2023-05-01