# Scalar functions

## Numeric functions¶

### `ABS`¶

Since: -

 `1` ``````ABS(col1) ``````

The absolute value of a value.

### `AS_VALUE`¶

Since: 0.9.0

 `1` ``````AS_VALUE(keyCol) ``````

Creates a copy of a key column in the value.

For example:

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

### `CEIL`¶

Since: -

 `1` ``````CEIL(col1) ``````

The ceiling of a value.

### `ENTRIES`¶

Since: 0.6.0

 `1` ``````ENTRIES(map MAP, sorted BOOLEAN) ``````

Constructs 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) ``````

The exponential of a value.

### `FLOOR`¶

Since: -

 `1` ``````FLOOR(col1) ``````

The floor of a value.

### `GENERATE_SERIES`¶

Since: 0.6.0

 `1` ``````GENERATE_SERIES(start, end) ``````
 `1` ``````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`.

### `LN`¶

Since: 0.6.0

 `1` ``````LN(col1) ``````

The natural logarithm of a value.

### `RANDOM`¶

Since: -

 `1` ``````RANDOM() ``````

Return a random DOUBLE value between 0.0 and 1.0.

### `ROUND`¶

Since: 0.6.0

 `1` ``````ROUND(col1) ``````
 `1` ``````ROUND(col1, scale) ``````

Round a value to the number of decimal places as specified by scale to the right of the decimal point. If scale is negative then 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) ``````

The sign of a numeric value 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

### `SQRT`¶

Since: 0.6.0

 `1` ``````SQRT(col1) ``````

The square root of a value.

## Collections¶

### `ARRAY`¶

Since: 0.7.0

 `1` ``````ARRAY[col1, col2, ...] ``````

Construct an array from a variable number of inputs.

### `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`.

### `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 the given array. The elements in the resulting string are separated by the chosen `delimiter`, which is an optional parameter that falls back to a comma `,`. The current implementation only allows for array elements of primitive ksqlDB types.

### `ARRAY_LENGTH`¶

Since: 0.8.0

 `1` ``````ARRAY_LENGTH(ARRAY[1, 2, 3]) ``````

Given an array, return the number of elements in the 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 within a given array of primitive elements (not arrays of other arrays, or maps, or structs, or combinations thereof).

Array entries are compared according to their natural sort order, which sorts the various data-types per the following examples: - `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)

If the array field is NULL, or contains only NULLs, then NULL is returned.

### `ARRAY_MIN`¶

Since: 0.10.0

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

Returns the minimum value from within a given array of primitive elements (not arrays of other arrays, or maps, or structs, or combinations thereof).

Array entries are compared according to their natural sort order, which sorts the various data-types per the following examples: - `array_min[-1, 2, NULL, 0] -> -1` - `array_min[false, NULL, true] -> false` - `array_min['Foo', 'Bar', NULL, 'baz'] -> 'Bar'`

If the array field is NULL, or contains only NULLs, then NULL is returned.

### `ARRAY_SORT`¶

Since: 0.10.0

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

Given an array of primitive elements (not arrays of other arrays, or maps, or structs, or combinations thereof), returns an array of the same elements sorted according to their natural sort order. Any NULLs contained in the array will always be moved to the end.

For example: - `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]`

If the array field is NULL then NULL is returned.

An optional second parameter can be used to specify whether to sort the elements in 'ASC'ending or 'DESC'ending order. If neither is specified then the default is ascending order.

### `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 in which they are first 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) ``````

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

### `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. This function is 1-indexed. ELT is the complement to FIELD.

### `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 is not considered to be equal to any value. FIELD is the complement to ELT.

### `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 does not contain a JSON array.

### `MAP`¶

Since: 0.7.0

 `1` ``````MAP(key VARCHAR := value, ...) ``````

Construct a map from specific key-value tuples.

### `MAP_KEYS`¶

Since: 0.10.0

 `1` ``````MAP_KEYS(a_map) ``````

Returns an array that contains all of the 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 of the 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 of the input maps are NULL.

Example:

 ```1 2 3``` ``````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.

## 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 does not 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: -

 `1` ``````CONCAT(col1, col2, 'hello', ..., col-n) ``````

Concatenate two or more string expressions. Any input strings which evaluate to NULL are replaced with empty string in the output.

### `CONCAT_WS`¶

Since: 0.10.0

 `1` ``````CONCAT_WS(separator, expr1, expr2, ...) ``````

Concatenates two or more string expressions, inserting a separator string 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`, and `base64`. Throws an exception if the provided encodings are not supported.

For example, to encode a string in `hex` to `utf8`, use `ENCODE(string, 'hex', 'utf8')`.

### `EXTRACTJSONFIELD`¶

Since: -

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

Given a STRING that contains JSON data, extract 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)` will extract the instance number from the above JSON object as a INT.

Note

EXTRACTJSONFIELD is useful for extracting data from JSON where either the schema of the JSON data is not static, or where the JSON data is embedded in a row 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 example above could be defined using a statement similar to this:

`CREATE STREAM LOGS (LOG STRUCT<CLOUD STRING, APP STRING, INSTANCE INT, ...) WITH (VALUE_FORMAT=JSON, ...)`

### `INITCAP`¶

Since: 0.6.0

 `1` ``````INITCAP(col1) ``````

Capitalize the first letter in each word and convert 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. Negative `position` causes the search to work from end to start of `string`.

If `occurrence` is provided, the position of 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: -

 `1` ``````LCASE(col1) ``````

Convert a string to lowercase.

### `LEN`¶

Since: -

 `1` ``````LEN(col1) ``````

The length of a string.

### `LPAD`¶

Since: 0.10.0

 `1` ``````LPAD(input, length, padding) ``````

Pads the input string, beginning from the left, with the specified padding string, until the target length is reached. If the input string is longer than the specified target length, it is truncated.

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

Examples:

 ```1 2 3 4``` ``````LPAD('Foo', 7, 'Bar') => 'BarBFoo' LPAD('Foo', 2, 'Bar') => 'Fo' LPAD('', 2, 'Bar') => 'Ba' LPAD('123', 5, '0') => '00123' ``````

### `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 then the default values, shown in the following example, are applied.

Set a given mask character to NULL to prevent any masking of that character type. For example: `MASK("My Test \$123")` will return `Xx-Xxxx--nnn`, applying all default masks. `MASK("My Test \$123", '*', NULL, '1', NULL)` will yield `*y *est \$111`.

### `MASK_KEEP_LEFT`¶

Since: 0.6.0

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

Similar to the `MASK` function above, except that the first or left-most `numChars` characters will not be masked in any way. For example: `MASK_KEEP_LEFT("My Test \$123", 4)` will return `My Txxx--nnn`.

### `MASK_KEEP_RIGHT`¶

Since: 0.6.0

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

Similar to the `MASK` function above, except that the last or right-most `numChars` characters will not be masked in any way. For example:`MASK_KEEP_RIGHT("My Test \$123", 4)` will return `Xx-Xxxx-\$123`.

### `MASK_LEFT`¶

Since: 0.6.0

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

Similar to the `MASK` function above, except that only the first or left-most `numChars` characters will have any masking applied to them. For example, `MASK_LEFT("My Test \$123", 4)` will return `Xx-Xest \$123`.

### `MASK_RIGHT`¶

Since: 0.6.0

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

Similar to the `MASK` function above, except that only the last or right-most `numChars` characters will have any masking applied to them. For example: `MASK_RIGHT("My Test \$123", 4)` will return `My Test -nnn`.

### `REPLACE`¶

Since: 0.6.0

 `1` ``````REPLACE(col1, 'foo', 'bar') ``````

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

### `REGEXP_EXTRACT`¶

Since: 0.8.0

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

Extract the first subtring matched by the regex pattern from the input.

A capturing group number can also be specified in order to return that specific group. If a number isn't specified, the entire substring is returned by default.

For example, `REGEXP_EXTRACT("(.*) (.*)", 'hello there', 2)` returns "there".

### `REGEXP_EXTRACT_ALL`¶

Since: 0.10.0

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

Extract all subtrings matched by the regex pattern from the input.

A capturing group number can also be specified in order to return that specific group. If a number isn't specified, the entire substring is returned by default.

For example, `REGEXP_EXTRACT("(\\w+) (\\w+)", 'hello there nice day', 2)` returns `['there', 'day']`.

### `REGEXP_REPLACE`¶

Since: 0.10.0

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

Replace all matches of a regex in an input string with a new string. If either the input string, regular expression, or 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, then 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, then an empty element is added to the array.

### `RPAD`¶

Since: 0.10.0

 `1` ``````RPAD(input, length, padding) ``````

Pads the input string, starting from the end, with the specified padding string until the target length is reached. If the input string is longer than the specified target length it will be truncated.

If the padding string is empty or NULL, or the target length is negative, then NULL is returned.

Examples:

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

### `SPLIT`¶

Since: 0.6.0

 `1` ``````SPLIT(col1, delimiter) ``````

Splits a string into an array of substrings based on a delimiter. If the delimiter is not found, then the original string is returned as the only element in the array. If the delimiter is empty, then all characters in the string are split. If either, string or delimiter, are NULL, then a NULL value is returned.

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

### `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 that 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: -

 `1` ``````SUBSTRING(col1, 2, 5) ``````
 `1` ``````SUBSTRING(str, pos, [len]) ``````

Returns a substring of `str` that starts at `pos` (first character is at position 1) and has length `len`, or continues to the end of the string.

For example, `SUBSTRING("stream", 1, 4)` returns "stre".

### `TRIM`¶

Since: -

 `1` ``````TRIM(col1) ``````

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

### `UCASE`¶

Since: -

 `1` ``````UCASE(col1) ``````

Convert a string to uppercase.

### `UUID`¶

Since: 0.10.0

 `1` ``````UUID() ``````

Create 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.

## 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.

Where the parameter type 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: -

 `1` ``````IFNULL(expression, altValue) ``````

If the provided `expression` is NULL, returns `altValue`, otherwise, returns `expression`.

Where the parameter type is a complex type, for example `ARRAY` or `STRUCT`, the contents of the complex type are not inspected.

## Date and time¶

### `UNIX_DATE`¶

Since: 0.6.0

 `1` ``````UNIX_DATE() ``````

Gets an integer representing days since epoch. The returned timestamp may differ depending on the local time of different ksqlDB Server instances.

### `UNIX_TIMESTAMP`¶

Since: 0.6.0

 `1` ``````UNIX_TIMESTAMP() ``````

Gets the Unix timestamp in milliseconds, represented as a BIGINT. The returned timestamp may differ depending on the local time of different ksqlDB Server instances.

### `DATETOSTRING`¶

Since: -

 `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: -

 `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: -

 `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: -

 `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", "Europe/London". For more information on timestamp formats, see DateTimeFormatter.

## URLs¶

Note

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/decoding, the `application/x-www-form-urlencoded` convention is followed.

### `URL_DECODE_PARAM`¶

 `1` ``````URL_DECODE_PARAM(col1) ``````

Since: 0.6.0

Unescapes the `URL-param-encoded`_ value in `col1`. This is the inverse of `URL_ENCODE_PARAM`.

• Input: `'url%20encoded`
• Output: `url encoded`

### `URL_ENCODE_PARAM`¶

 `1` ``````URL_ENCODE_PARAM(col1) ``````

Since: 0.6.0

Escapes the value of `col1` such that it can safely be used in URL query parameters. Note that this is not the same as encoding a value for use in the path portion of a URL.

• Input: `url encoded`
• Output: `'url%20encoded`

### `URL_EXTRACT_FRAGMENT`¶

 `1` ``````URL_EXTRACT_FRAGMENT(url) ``````

Since: 0.6.0

Extract the fragment portion of the specified value. Returns NULL if `url` is not a valid URL or if the fragment does not exist. Any encoded value will be decoded.

• Input: `http://test.com#frag`,
• Output: `frag`

• Input: `http://test.com#frag%20space`,

• Output: `frag space`

### `URL_EXTRACT_HOST`¶

 `1` ``````URL_EXTRACT_HOST(url) ``````

Since: 0.6.0

Extract the host-name portion of the specified value. Returns NULL if the `url` is not a valid
URI according to RFC-2396.

• Input: `http://test.com:8080/path`,
• Output: `test.com`

### `URL_EXTRACT_PARAMETER`¶

Since: 0.6.0

 `1` ``````URL_EXTRACT_PARAMETER(url, parameter_name) ``````

Extract 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. Encodes the param and decodes the output (see examples).

To get all of the parameter values from a URL as a single string, see `URL_EXTRACT_QUERY.`

• Input: `http://test.com?a%20b=c%20d`, `a b`
• Output: `c d`

• Input: `http://test.com?a=foo&b=bar`, `b`

• Output: `bar`

### `URL_EXTRACT_PATH`¶

 `1` ``````URL_EXTRACT_PATH(url) ``````

Since: 0.6.0

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

• Input: `http://test.com/path/to#a`
• Output: `path/to`

### `URL_EXTRACT_PORT`¶

 `1` ``````URL_EXTRACT_PORT(url) ``````

Since: 0.6.0

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

• Input: `http://localhost:8080/path`
• Output: `8080`

### `URL_EXTRACT_PROTOCOL`¶

 `1` ``````URL_EXTRACT_PROTOCOL(url) ``````

Since: 0.6.0

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

• Input: `http://test.com?a=foo&b=bar`
• Output: `http`

### `URL_EXTRACT_QUERY`¶

Since: 0.6.0

 `1` ``````URL_EXTRACT_QUERY(url) ``````

Extract the decoded query-string portion of `url`. Returns NULL if no query-string is
present or `url` is not a valid URI.

• Input: `http://test.com?a=foo%20bar&b=baz`
• Output: `a=foo bar&b=baz`

Last update: 2020-08-10