| <!--- |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| --> |
| |
| # Scalar Functions |
| |
| ## Math Functions |
| |
| - [abs](#abs) |
| - [acos](#acos) |
| - [asin](#asin) |
| - [atan](#atan) |
| - [atan2](#atan2) |
| - [ceil](#ceil) |
| - [cos](#cos) |
| - [exp](#exp) |
| - [floor](#floor) |
| - [ln](#ln) |
| - [log10](#log10) |
| - [log2](#log2) |
| - [power](#power) |
| - [random](#random) |
| - [round](#round) |
| - [signum](#signum) |
| - [sin](#sin) |
| - [sqrt](#sqrt) |
| - [cbrt](#cbrt) |
| - [tan](#tan) |
| - [trunc](#trunc) |
| |
| ### `abs` |
| |
| Returns the absolute value of a number. |
| |
| ``` |
| abs(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `acos` |
| |
| Returns the arc cosine or inverse cosine of a number. |
| |
| ``` |
| acos(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `asin` |
| |
| Returns the arc sine or inverse sine of a number. |
| |
| ``` |
| asin(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `atan` |
| |
| Returns the arc tangent or inverse tangent of a number. |
| |
| ``` |
| atan(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `atan2` |
| |
| Returns the arc tangent or inverse tangent of `expression_y / expression_x`. |
| |
| ``` |
| atan2(expression_y, expression_x) |
| ``` |
| |
| #### Arguments |
| |
| - **expression_y**: First numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| - **expression_x**: Second numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `ceil` |
| |
| Returns the nearest integer greater than or equal to a number. |
| |
| ``` |
| ceil(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `cos` |
| |
| Returns the cosine of a number. |
| |
| ``` |
| cos(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `exp` |
| |
| Returns the base-e exponential of a number. |
| |
| ``` |
| exp(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to use as the exponent. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `floor` |
| |
| Returns the nearest integer less than or equal to a number. |
| |
| ``` |
| floor(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `ln` |
| |
| Returns the natural logarithm of a number. |
| |
| ``` |
| ln(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `log10` |
| |
| Returns the base-10 logarithm of a number. |
| |
| ``` |
| log10(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `log2` |
| |
| Returns the base-2 logarithm or a number. |
| |
| ``` |
| log2(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `power` |
| |
| Returns a base number raised to the power of an exponent. |
| |
| ``` |
| power(base, exponent) |
| ``` |
| |
| #### Arguments |
| |
| - **power**: Base numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| - **exponent**: Exponent numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `random` |
| |
| Returns a random float value between 0 and 1. |
| The random seed is unique to each row. |
| |
| ``` |
| random() |
| ``` |
| |
| ### `round` |
| |
| Rounds a number to the nearest integer. |
| |
| ``` |
| round(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `signum` |
| |
| Returns the sign of a number. |
| Negative numbers return `-1`. |
| Zero and positive numbers return `1`. |
| |
| ``` |
| signum(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `sin` |
| |
| Returns the sine of a number. |
| |
| ``` |
| sin(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `sqrt` |
| |
| Returns the square root of a number. |
| |
| ``` |
| sqrt(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `cbrt` |
| |
| Returns the cube root of a number. |
| |
| ``` |
| cbrt(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `tan` |
| |
| Returns the tangent of a number. |
| |
| ``` |
| tan(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `trunc` |
| |
| Truncates a number toward zero (at the decimal point). |
| |
| ``` |
| trunc(numeric_expression) |
| ``` |
| |
| #### Arguments |
| |
| - **numeric_expression**: Numeric expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ## Conditional Functions |
| |
| - [coalesce](#coalesce) |
| - [nullif](#nullif) |
| |
| ### `coalesce` |
| |
| Returns the first of its arguments that is not _null_. |
| Returns _null_ if all arguments are _null_. |
| This function is often used to substitute a default value for _null_ values. |
| |
| ``` |
| coalesce(expression1[, ..., expression_n]) |
| ``` |
| |
| #### Arguments |
| |
| - **expression1, expression_n**: |
| Expression to use if previous expressions are _null_. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| Pass as many expression arguments as necessary. |
| |
| ### `nullif` |
| |
| Returns _null_ if _expression1_ equals _expression2_; otherwise it returns _expression1_. |
| This can be used to perform the inverse operation of [`coalesce`](#coalesce). |
| |
| ``` |
| nullif(expression1, expression2) |
| ``` |
| |
| #### Arguments |
| |
| - **expression1**: Expression to compare and return if equal to expression2. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| - **expression2**: Expression to compare to expression1. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ## String Functions |
| |
| - [ascii](#ascii) |
| - [bit_length](#bit_length) |
| - [btrim](#btrim) |
| - [char_length](#char_length) |
| - [character_length](#character_length) |
| - [concat](#concat) |
| - [concat_ws](#concat_ws) |
| - [chr](#chr) |
| - [initcap](#initcap) |
| - [left](#left) |
| - [length](#length) |
| - [lower](#lower) |
| - [lpad](#lpad) |
| - [ltrim](#ltrim) |
| - [octet_length](#octet_length) |
| - [repeat](#repeat) |
| - [replace](#replace) |
| - [reverse](#reverse) |
| - [right](#right) |
| - [rpad](#rpad) |
| - [rtrim](#rtrim) |
| - [split_part](#split_part) |
| - [starts_with](#starts_with) |
| - [strpos](#strpos) |
| - [substr](#substr) |
| - [to_hex](#to_hex) |
| - [translate](#translate) |
| - [trim](#trim) |
| - [upper](#upper) |
| |
| ### `ascii` |
| |
| Returns the ASCII value of the first character in a string. |
| |
| ``` |
| ascii(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [chr](#chr) |
| |
| ### `bit_length` |
| |
| Returns the bit length of a string. |
| |
| ``` |
| bit_length(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [length](#length), |
| [octet_length](#octet_length) |
| |
| ### `btrim` |
| |
| Trims the specified trim string from the start and end of a string. |
| If no trim string is provided, all whitespace is removed from the start and end |
| of the input string. |
| |
| ``` |
| btrim(str[, trim_str]) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **trim_str**: String expression to trim from the beginning and end of the input string. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| _Default is whitespace characters_. |
| |
| **Related functions**: |
| [ltrim](#ltrim), |
| [rtrim](#rtrim), |
| [trim](#trim) |
| |
| ### `char_length` |
| |
| _Alias of [length](#length)._ |
| |
| ### `character_length` |
| |
| _Alias of [length](#length)._ |
| |
| ### `concat` |
| |
| Concatenates multiple strings together. |
| |
| ``` |
| concat(str[, ..., str_n]) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to concatenate. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **str_n**: Subsequent string column or literal string to concatenate. |
| |
| **Related functions**: |
| [contcat_ws](#contcat_ws) |
| |
| ### `concat_ws` |
| |
| Concatenates multiple strings together with a specified separator. |
| |
| ``` |
| concat(separator, str[, ..., str_n]) |
| ``` |
| |
| #### Arguments |
| |
| - **separator**: Separator to insert between concatenated strings. |
| - **str**: String expression to concatenate. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **str_n**: Subsequent string column or literal string to concatenate. |
| |
| **Related functions**: |
| [concat](#concat) |
| |
| ### `chr` |
| |
| Returns the character with the specified ASCII or Unicode code value. |
| |
| ``` |
| chr(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression containing the ASCII or Unicode code value to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic or |
| string operators. |
| |
| **Related functions**: |
| [ascii](#ascii) |
| |
| ### `initcap` |
| |
| Capitalizes the first character in each word in the input string. |
| Words are delimited by non-alphanumeric characters. |
| |
| ``` |
| initcap(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [lower](#lower), |
| [upper](#upper) |
| |
| ### `left` |
| |
| Returns a specified number of characters from the left side of a string. |
| |
| ``` |
| left(str, n) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **n**: Number of characters to return. |
| |
| **Related functions**: |
| [right](#right) |
| |
| ### `length` |
| |
| Returns the number of characters in a string. |
| |
| ``` |
| length(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| #### Aliases |
| |
| - char_length |
| - character_length |
| |
| **Related functions**: |
| [bit_length](#bit_length), |
| [octet_length](#octet_length) |
| |
| ### `lower` |
| |
| Converts a string to lower-case. |
| |
| ``` |
| lower(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [initcap](#initcap), |
| [upper](#upper) |
| |
| ### `lpad` |
| |
| Pads the left side a string with another string to a specified string length. |
| |
| ``` |
| lpad(str, n[, padding_str]) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **n**: String length to pad to. |
| - **padding_str**: String expression to pad with. |
| Can be a constant, column, or function, and any combination of string operators. |
| _Default is a space._ |
| |
| **Related functions**: |
| [rpad](#rpad) |
| |
| ### `ltrim` |
| |
| Removes leading spaces from a string. |
| |
| ``` |
| ltrim(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [btrim](#btrim), |
| [rtrim](#rtrim), |
| [trim](#trim) |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `octet_length` |
| |
| Returns the length of a string in bytes. |
| |
| ``` |
| octet_length(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [bit_length](#bit_length), |
| [length](#length) |
| |
| ### `repeat` |
| |
| Returns a string with an input string repeated a specified number. |
| |
| ``` |
| repeat(str, n) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to repeat. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **n**: Number of times to repeat the input string. |
| |
| ### `replace` |
| |
| Replaces all occurrences of a specified substring in a string with a new substring. |
| |
| ``` |
| replace(str, substr, replacement) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to repeat. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **substr**: Substring expression to replace in the input string. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **replacement**: Replacement substring expression. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `reverse` |
| |
| Reverses the character order of a string. |
| |
| ``` |
| reverse(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to repeat. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `right` |
| |
| Returns a specified number of characters from the right side of a string. |
| |
| ``` |
| right(str, n) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **n**: Number of characters to return. |
| |
| **Related functions**: |
| [left](#left) |
| |
| ### `rpad` |
| |
| right side a string with another string to a specified string length. |
| |
| ``` |
| rpad(str, n[, padding_str]) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **n**: String length to pad to. |
| - **padding_str**: String expression to pad with. |
| Can be a constant, column, or function, and any combination of string operators. |
| _Default is a space._ |
| |
| **Related functions**: |
| [lpad](#lpad) |
| |
| ### `rtrim` |
| |
| Removes trailing spaces from a string. |
| |
| ``` |
| rtrim(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [btrim](#btrim), |
| [ltrim](#ltrim), |
| [trim](#trim) |
| |
| ### `split_part` |
| |
| Splits a string based on a specified delimiter and returns the substring a the |
| specified position. |
| |
| ``` |
| split_part(str, delimiter, pos) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to spit. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **delimiter**: String or character to split on. |
| - **pos**: Position of the part to return. |
| |
| ### `starts_with` |
| |
| Tests if a string starts with a substring. |
| |
| ``` |
| starts_with(str, substr) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to test. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **substr**: Substring to test for. |
| |
| ### `strpos` |
| |
| Returns the starting position of a specified substring in a string. |
| Positions begin at 1. |
| If the substring does not exist in the string, the function returns 0. |
| |
| ``` |
| strpos(str, substr) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **substr**: Substring expression to search for. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `substr` |
| |
| Extracts a substring of a specified number of characters from a specific |
| starting position in a string. |
| |
| ``` |
| substr(str, start_pos[, length]) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **start_pos**: Character position to start the substring at. |
| The first character in the string has a position of 1. |
| - **length**: Number of characters to extract. |
| If not specified, returns the rest of the string after the start position. |
| |
| ### `translate` |
| |
| Translates characters in a string to specified translation characters. |
| |
| ``` |
| translate(str, chars, translation) |
| ``` |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **chars**: Characters to translate. |
| - **translation**: Translation characters. Translation characters replace only |
| characters at the same position in the **chars** string. |
| |
| ### `to_hex` |
| |
| Converts an integer to a hexadecimal string. |
| |
| ``` |
| to_hex(int) |
| ``` |
| |
| #### Arguments |
| |
| - **int**: Integer expression to convert. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `trim` |
| |
| Removes leading and trailing spaces from a string. |
| |
| ``` |
| trim(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [btrim](#btrim), |
| [ltrim](#ltrim), |
| [rtrim](#rtrim) |
| |
| ### `upper` |
| |
| Converts a string to upper-case. |
| |
| ``` |
| upper(str) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| **Related functions**: |
| [initcap](#initcap), |
| [lower](#lower) |
| |
| ## Regular Expression Functions |
| |
| Apache DataFusion uses the POSIX regular expression syntax and |
| supports the following regular expression functions: |
| |
| - [regexp_match](#regexp_match) |
| - [regexp_replace](#regexp_replace) |
| |
| ### `regexp_match` |
| |
| Returns a list of regular expression matches in a string. |
| |
| ``` |
| regexp_match(str, regexp) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **regexp**: Regular expression to match against. |
| Can be a constant, column, or function. |
| |
| ### `regexp_replace` |
| |
| Replaces substrings in a string that match a regular expression. |
| |
| ``` |
| regexp_replace(str, regexp, replacement, flags) |
| ``` |
| |
| #### Arguments |
| |
| - **str**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **regexp**: Regular expression to match against. |
| Can be a constant, column, or function. |
| - **replacement**: Replacement string expression. |
| Can be a constant, column, or function, and any combination of string operators. |
| - **flags**: Regular expression flags that control the behavior of the |
| regular expression. The following flags are supported. |
| - **g**: (global) Search globally and don't return after the first match. |
| - **i**: (insensitive) Ignore case when matching. |
| |
| ## Time and Date Functions |
| |
| - [now](#now) |
| - [date_bin](#date_bin) |
| - [date_trunc](#date_trunc) |
| - [date_part](#date_part) |
| - [extract](#extract) |
| - [to_timestamp](#to_timestamp) |
| - [to_timestamp_millis](#to_timestamp_millis) |
| - [to_timestamp_micros](#to_timestamp_micros) |
| - [to_timestamp_seconds](#to_timestamp_seconds) |
| - [from_unixtime](#from_unixtime) |
| |
| ### `now` |
| |
| Returns the current UTC timestamp. |
| |
| The `now()` return value is determined at query time and will return the same timestamp, |
| no matter when in the query plan the function executes. |
| |
| ``` |
| now() |
| ``` |
| |
| ### `date_bin` |
| |
| Calculates time intervals and returns the start of the interval nearest to the specified timestamp. |
| Use `date_bin` to downsample time series data by grouping rows into time-based "bins" or "windows" |
| and applying an aggregate or selector function to each window. |
| |
| For example, if you "bin" or "window" data into 15 minute intervals, an input |
| timestamp of `2023-01-01T18:18:18Z` will be updated to the start time of the 15 |
| minute bin it is in: `2023-01-01T18:15:00Z`. |
| |
| ``` |
| date_bin(interval, expression, origin-timestamp) |
| ``` |
| |
| #### Arguments |
| |
| - **interval**: Bin interval. |
| - **expression**: Time expression to operate on. |
| Can be a constant, column, or function. |
| - **timestamp**: Starting point used to determine bin boundaries. |
| |
| The following intervals are supported: |
| |
| - nanoseconds |
| - microseconds |
| - milliseconds |
| - seconds |
| - minutes |
| - hours |
| - days |
| - weeks |
| - months |
| - years |
| - century |
| |
| ### `date_trunc` |
| |
| Truncates a timestamp value to a specified precision. |
| |
| ``` |
| date_trunc(precision, expression) |
| ``` |
| |
| #### Arguments |
| |
| - **precision**: Time precision to truncate to. |
| The following precisions are supported: |
| |
| - year |
| - month |
| - week |
| - day |
| - hour |
| - minute |
| - second |
| |
| - **expression**: Time expression to operate on. |
| Can be a constant, column, or function. |
| |
| ### `date_part` |
| |
| Returns the specified part of the date as an integer. |
| |
| ``` |
| date_part(part, expression) |
| ``` |
| |
| #### Arguments |
| |
| - **part**: Part of the date to return. |
| The following date parts are supported: |
| |
| - year |
| - month |
| - week _(week of the year)_ |
| - day _(day of the month)_ |
| - hour |
| - minute |
| - second |
| - millisecond |
| - microsecond |
| - nanosecond |
| - dow _(day of the week)_ |
| - doy _(day of the year)_ |
| |
| - **expression**: Time expression to operate on. |
| Can be a constant, column, or function. |
| |
| ### `extract` |
| |
| Returns a sub-field from a time value as an integer. |
| Similar to `date_part`, but with different arguments. |
| |
| ``` |
| extract(field FROM source) |
| ``` |
| |
| #### Arguments |
| |
| - **field**: Part or field of the date to return. |
| The following date fields are supported: |
| |
| - year |
| - month |
| - week _(week of the year)_ |
| - day _(day of the month)_ |
| - hour |
| - minute |
| - second |
| - millisecond |
| - microsecond |
| - nanosecond |
| - dow _(day of the week)_ |
| - doy _(day of the year)_ |
| |
| - **source**: Source time expression to operate on. |
| Can be a constant, column, or function. |
| |
| ### `to_timestamp` |
| |
| Converts a value to RFC3339 nanosecond timestamp format (`YYYY-MM-DDT00:00:00.000000000Z`). |
| Supports timestamp, integer, and unsigned integer types as input. |
| Integers and unsigned integers are parsed as Unix nanosecond timestamps and |
| return the corresponding RFC3339 nanosecond timestamp. |
| |
| ``` |
| to_timestamp(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `to_timestamp_millis` |
| |
| Converts a value to RFC3339 millisecond timestamp format (`YYYY-MM-DDT00:00:00.000Z`). |
| Supports timestamp, integer, and unsigned integer types as input. |
| Integers and unsigned integers are parsed as Unix nanosecond timestamps and |
| return the corresponding RFC3339 timestamp. |
| |
| ``` |
| to_timestamp_millis(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `to_timestamp_micros` |
| |
| Converts a value to RFC3339 microsecond timestamp format (`YYYY-MM-DDT00:00:00.000000Z`). |
| Supports timestamp, integer, and unsigned integer types as input. |
| Integers and unsigned integers are parsed as Unix nanosecond timestamps and |
| return the corresponding RFC3339 timestamp. |
| |
| ``` |
| to_timestamp_micros(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `to_timestamp_seconds` |
| |
| Converts a value to RFC3339 second timestamp format (`YYYY-MM-DDT00:00:00Z`). |
| Supports timestamp, integer, and unsigned integer types as input. |
| Integers and unsigned integers are parsed as Unix nanosecond timestamps and |
| return the corresponding RFC3339 timestamp. |
| |
| ``` |
| to_timestamp_seconds(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ### `from_unixtime` |
| |
| Converts an integer to RFC3339 timestamp format (`YYYY-MM-DDT00:00:00.000000000Z`). |
| Input is parsed as a Unix nanosecond timestamp and returns the corresponding |
| RFC3339 timestamp. |
| |
| ``` |
| from_unixtime(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression to operate on. |
| Can be a constant, column, or function, and any combination of arithmetic operators. |
| |
| ## Hashing Functions |
| |
| - [md5](#md5) |
| - [sha224](#sha224) |
| - [sha256](#sha256) |
| - [sha384](#sha384) |
| - [sha512](#sha512) |
| |
| ### `md5` |
| |
| Computes an MD5 128-bit checksum for a string expression. |
| |
| ``` |
| md5(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `sha224` |
| |
| Computes the SHA-224 hash of a binary string. |
| |
| ``` |
| sha224(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `sha256` |
| |
| Computes the SHA-256 hash of a binary string. |
| |
| ``` |
| sha256(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `sha384` |
| |
| Computes the SHA-384 hash of a binary string. |
| |
| ``` |
| sha384(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ### `sha512` |
| |
| Computes the SHA-512 hash of a binary string. |
| |
| ``` |
| sha512(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: String expression to operate on. |
| Can be a constant, column, or function, and any combination of string operators. |
| |
| ## Other Functions |
| |
| - [array](#array) |
| - [arrow_cast](#arrow_cast) |
| - [arrow_typeof](#arrow_typeof) |
| - [struct](#struct) |
| |
| ### `array` |
| |
| Returns an Arrow array using the specified input expressions. |
| |
| ``` |
| array(expression1[, ..., expression_n]) |
| ``` |
| |
| #### Arguments |
| |
| - **expression_n**: Expression to include in the output array. |
| Can be a constant, column, or function, and any combination of arithmetic or |
| string operators. |
| |
| ### `arrow_cast` |
| |
| Casts a value to a specific Arrow data type: |
| |
| ``` |
| arrow_cast(expression, datatype) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression to cast. |
| Can be a constant, column, or function, and any combination of arithmetic or |
| string operators. |
| - **datatype**: [Arrow data type](https://arrow.apache.org/datafusion/user-guide/sql/data_types.html) |
| to cast to. |
| |
| ### `arrow_typeof` |
| |
| Returns the underlying Arrow data type of the expression: |
| |
| ``` |
| arrow_typeof(expression) |
| ``` |
| |
| #### Arguments |
| |
| - **expression**: Expression to evaluate. |
| Can be a constant, column, or function, and any combination of arithmetic or |
| string operators. |
| |
| ### `struct` |
| |
| Returns an Arrow struct using the specified input expressions. |
| Fields in the returned struct use the `cN` naming convention. |
| For example: `c0`, `c1`, `c2`, etc. |
| |
| ``` |
| struct(expression1[, ..., expression_n]) |
| ``` |
| |
| #### Arguments |
| |
| - **expression_n**: Expression to include in the output struct. |
| Can be a constant, column, or function, and any combination of arithmetic or |
| string operators. |
