opensearch-docs-cn/_search-plugins/sql/functions.md

---
layout: default
title: Functions
parent: SQL and PPL
nav_order: 10
redirect_from:
  - /search-plugins/sql/functions/
---

# Functions

You must enable fielddata in the document mapping for most string functions to work properly.

The specification shows the return type of the function with a generic type `T` as the argument.
For example, `abs(number T) -> T` means that the function `abs` accepts a numerical argument of type `T`, which could be any subtype of the `number` type, and it returns the actual type of `T` as the return type.

The SQL plugin supports the following common functions shared across the SQL and PPL languages.

## Mathematical

Function | Specification | Example
:--- | :--- | :---
abs | `abs(number T) -> T` | `SELECT abs(0.5) FROM my-index LIMIT 1`
add | `add(number T, number) -> T` | `SELECT add(1, 5) FROM my-index LIMIT 1`
cbrt | `cbrt(number T) -> T` | `SELECT cbrt(0.5) FROM my-index LIMIT 1`
ceil | `ceil(number T) -> T` | `SELECT ceil(0.5) FROM my-index LIMIT 1`
conv | `conv(string T, int a, int b) -> T` | `SELECT CONV('12', 10, 16), CONV('2C', 16, 10), CONV(12, 10, 2), CONV(1111, 2, 10) FROM my-index LIMIT 1`
crc32 | `crc32(string T) -> T` | `SELECT crc32('MySQL') FROM my-index LIMIT 1`
divide | `divide(number T, number) -> T` | `SELECT divide(1, 0.5) FROM my-index LIMIT 1`
e | `e() -> double` | `SELECT e() FROM my-index LIMIT 1`
exp | `exp(number T) -> T` | `SELECT exp(0.5) FROM my-index LIMIT 1`
expm1 | `expm1(number T) -> T` | `SELECT expm1(0.5) FROM my-index LIMIT 1`
floor | `floor(number T) -> T` | `SELECT floor(0.5) AS Rounded_Down FROM my-index LIMIT 1`
ln | `ln(number T) -> double` | `SELECT ln(10) FROM my-index LIMIT 1`
log | `log(number T) -> double` or `log(number T, number) -> double` | `SELECT log(10) FROM my-index LIMIT 1`
log2 | `log2(number T) -> double` | `SELECT log2(10) FROM my-index LIMIT 1`
log10 | `log10(number T) -> double` | `SELECT log10(10) FROM my-index LIMIT 1`
mod | `mod(number T, number) -> T` | `SELECT modulus(2, 3) FROM my-index LIMIT 1`
multiply | `multiply(number T, number) -> number` | `SELECT multiply(2, 3) FROM my-index LIMIT 1`
pi | `pi() -> double` | `SELECT pi() FROM my-index LIMIT 1`
pow | `pow(number T) -> T` or `pow(number T, number) -> T` | `SELECT pow(2, 3) FROM my-index LIMIT 1`
power | `power(number T) -> T` or `power(number T, number) -> T` | `SELECT power(2, 3) FROM my-index LIMIT 1`
rand | `rand() -> number` or `rand(number T) -> T` | `SELECT rand(0.5) FROM my-index LIMIT 1`
rint | `rint(number T) -> T` | `SELECT rint(1.5) FROM my-index LIMIT 1`
round | `round(number T) -> T` | `SELECT round(1.5) FROM my-index LIMIT 1`
sign | `sign(number T) -> T` | `SELECT sign(1.5) FROM my-index LIMIT 1`
signum | `signum(number T) -> T` | `SELECT signum(0.5) FROM my-index LIMIT 1`
sqrt | `sqrt(number T) -> T` | `SELECT sqrt(0.5) FROM my-index LIMIT 1`
strcmp | `strcmp(string T, string T) -> T` | `SELECT strcmp('hello', 'hello') FROM my-index LIMIT 1`
subtract | `subtract(number T, number) -> T` | `SELECT subtract(3, 2) FROM my-index LIMIT 1`
truncate | `truncate(number T, number T) -> T` | `SELECT truncate(56.78, 1) FROM my-index LIMIT 1`
/ | `number [op] number -> number` | `SELECT 1 / 100 FROM my-index LIMIT 1`
% | `number [op] number -> number` | `SELECT 1 % 100 FROM my-index LIMIT 1`

## Trigonometric

Function | Specification | Example
:--- | :--- | :---
acos | `acos(number T) -> double` | `SELECT acos(0.5) FROM my-index LIMIT 1`
asin | `asin(number T) -> double` | `SELECT asin(0.5) FROM my-index LIMIT 1`
atan | `atan(number T) -> double` | `SELECT atan(0.5) FROM my-index LIMIT 1`
atan2 | `atan2(number T, number) -> double` | `SELECT atan2(1, 0.5) FROM my-index LIMIT 1`
cos | `cos(number T) -> double` | `SELECT cos(0.5) FROM my-index LIMIT 1`
cosh | `cosh(number T) -> double` | `SELECT cosh(0.5) FROM my-index LIMIT 1`
cot | `cot(number T) -> double` | `SELECT cot(0.5) FROM my-index LIMIT 1`
degrees | `degrees(number T) -> double` | `SELECT degrees(0.5) FROM my-index LIMIT 1`
radians | `radians(number T) -> double` | `SELECT radians(0.5) FROM my-index LIMIT 1`
sin | `sin(number T) -> double` | `SELECT sin(0.5) FROM my-index LIMIT 1`
sinh | `sinh(number T) -> double` | `SELECT sinh(0.5) FROM my-index LIMIT 1`
tan | `tan(number T) -> double` | `SELECT tan(0.5) FROM my-index LIMIT 1`

## Date and time
Functions marked with * are only available in SQL.

Function | Specification | Example
:--- | :--- | :---
adddate | `adddate(date, INTERVAL expr unit) -> date` | `SELECT adddate(date('2020-08-26'), INTERVAL 1 hour) FROM my-index LIMIT 1`
addtime | `addtime(date, date) -> date` | `SELECT addtime(date('2008-12-12'), date('2008-12-12'))`
convert_tz | `convert_tz(date, string, string) -> date` | `SELECT convert_tz('2008-12-25 05:30:00', '+00:00', 'America/Los_Angeles')`
curtime | `curtime() -> time` | `SELECT curtime()`
curdate | `curdate() -> date` | `SELECT curdate() FROM my-index LIMIT 1`
current_date | `current_date() -> date` | `SELECT current_date() FROM my-index LIMIT 1`
current_time | `current_time() -> time` | `SELECT current_time()`
current_timestamp | `current_timestamp() -> date` | `SELECT current_timestamp() FROM my-index LIMIT 1`
date | `date(date) -> date` | `SELECT date() FROM my-index LIMIT 1`
datediff | `datediff(date, date) -> integer` | `SELECT datediff(date('2000-01-02'), date('2000-01-01'))`
datetime | `datetime(string) -> datetime` | `SELECT datetime('2008-12-25 00:00:00')`
date_add | `date_add(date, INTERVAL integer UNIT)` | `SELECT date_add('2020-08-26'), INTERVAL 1 HOUR)`
date_format | `date_format(date, string) -> string` or `date_format(date, string, string) -> string` | `SELECT date_format(date, 'Y') FROM my-index LIMIT 1`
date_sub | `date_sub(date, INTERVAL expr unit) -> date` | `SELECT date_sub(date('2008-01-02'), INTERVAL 31 day) FROM my-index LIMIT 1`
dayofmonth | `dayofmonth(date) -> integer` | `SELECT dayofmonth(date) FROM my-index LIMIT 1`
day | `day(date) -> integer` | `SELECT day(date('2020-08-25'))`
dayname | `dayname(date) -> string` | `SELECT dayname(date('2020-08-26')) FROM my-index LIMIT 1`
dayofmonth |  `dayofmonth(date) -> integer` | `SELECT dayofmonth(date) FROM my-index LIMIT 1`
dayofweek |  `dayofweek(date) -> integer` | `SELECT dayofweek(date) FROM my-index LIMIT 1`
dayofyear | `dayofyear(date) -> integer` | `SELECT dayofyear(date('2020-08-26')) FROM my-index LIMIT 1`
dayofweek | `dayofweek(date) -> integer` | `SELECT dayofweek(date('2020-08-26')) FROM my-index LIMIT 1`
day_of_month\* | `day_of_month(date) -> integer` | `SELECT day_of_month(date) FROM my-index LIMIT 1`
day_of_week\* | `day_of_week(date) -> integer` | `SELECT day_of_week(date('2020-08-26')) FROM my-index LIMIT 1`
day_of_year\* | `day_of_year(date) -> integer` | `SELECT day_of_year(date('2020-08-26')) FROM my-index LIMIT 1`
extract\* | `extract(part FROM date) -> integer` | `SELECT extract(MONTH FROM datetime('2020-08-26 10:11:12'))`
from_days | `from_days(N) -> integer` | `SELECT from_days(733687) FROM my-index LIMIT 1`
from_unixtime | `from_unixtime(N) -> date` | `SELECT from_unixtime(1220249547)`
get_format | `get_format(PART, string) -> string` | `SELECT get_format(DATE, 'USA')`
hour | `hour(time) -> integer` | `SELECT hour((time '01:02:03')) FROM my-index LIMIT 1`
hour_of_day\* | `hour_of_day(time) -> integer` | `SELECT hour_of_day((time '01:02:03')) FROM my-index LIMIT 1`
last_day\* | `last_day(date) -> integer` | `SELECT last_day(date('2020-08-26'))`
localtime | `localtime() -> date` | `SELECT localtime() FROM my-index LIMIT 1`
localtimestamp | `localtimestamp() -> date` | `SELECT localtimestamp() FROM my-index LIMIT 1`
makedate | `makedate(double, double) -> date` | `SELECT makedate(1945, 5.9)`
maketime | `maketime(integer, integer, integer) -> date` | `SELECT maketime(1, 2, 3) FROM my-index LIMIT 1`
microsecond | `microsecond(expr) -> integer` | `SELECT microsecond((time '01:02:03.123456')) FROM my-index LIMIT 1`
minute | `minute(expr) -> integer` | `SELECT minute((time '01:02:03')) FROM my-index LIMIT 1`
minute_of_day\* | `minute_of_day(expr) -> integer` | `SELECT minute_of_day((time '01:02:03')) FROM my-index LIMIT 1`
minute_of_hour\* | `minute_of_hour(expr) -> integer` | `SELECT minute_of_hour((time '01:02:03')) FROM my-index LIMIT 1`
month | `month(date) -> integer` | `SELECT month(date) FROM my-index`
month_of_year\* | `month_of_year(date) -> integer` | `SELECT month_of_year(date) FROM my-index`
monthname | `monthname(date) -> string` | `SELECT monthname(date) FROM my-index`
now | `now() -> date` | `SELECT now() FROM my-index LIMIT 1`
period_add | `period_add(integer, integer)` | `SELECT period_add(200801, 2)`
period_diff | `period_diff(integer, integer)` | `SELECT period_diff(200802, 200703)`
quarter | `quarter(date) -> integer` | `SELECT quarter(date('2020-08-26')) FROM my-index LIMIT 1`
second | `second(time) -> integer` | `SELECT second((time '01:02:03')) FROM my-index LIMIT 1`
second_of_minute\* | `second_of_minute(time) -> integer` | `SELECT second_of_minute((time '01:02:03')) FROM my-index LIMIT 1`
sec_to_time\* | `sec_to_time(integer) -> date` | `SELECT sec_to_time(10000)`
subdate | `subdate(date, INTERVAL expr unit) -> date, datetime` | `SELECT subdate(date('2008-01-02'), INTERVAL 31 day) FROM my-index LIMIT 1`
subtime | `subtime(date, date) -> date` | `SELECT subtime(date('2008-12-12'), date('2008-11-15'))`
str_to_date\* | `str_to_date(string, format) -> date` | `SELECT str_to_date("March 10 2000", %M %d %Y")`
time | `time(expr) -> time` | `SELECT time('13:49:00') FROM my-index LIMIT 1`
timediff | `timediff(time, time) -> time` | `SELECT timediff(time('23:59:59'), time('13:00:00'))`
timestamp | `timestamp(date) -> date` | `SELECT timestamp(date) FROM my-index LIMIT 1`
timestampadd | `timestampadd(interval, integer, date) -> date)` | `SELECT timestampadd(DAY, 17, datetime('2000-01-01 00:00:00'))`
timestampdiff | `timestampdiff(interval, date, date) -> integer` | `SELECT timestampdiff(YEAR, '1997-01-01 00:00:00, '2001-03-06 00:00:00')`
time_format | `time_format(date, string) -> string` | `SELECT time_format('1998-01-31 13:14:15.012345', '%f %H %h %I %i %p %r %S %s %T')`
time_to_sec | `time_to_sec(time) -> long` | `SELECT time_to_sec(time '22:23:00') FROM my-index LIMIT 1`
to_days | `to_days(date) -> long` | `SELECT to_days(date '2008-10-07') FROM my-index LIMIT 1`
to_seconds | `to_seconds(date) -> integer` | `SELECT to_seconds(date('2008-10-07')`
unix_timestamp | `unix_timestamp(date) -> double` | `SELECT unix_timestamp(timestamp('1996-11-15 17:05:42'))`
utc_date | `utc_date() -> date` | `SELECT utc_date()`
utc_time | `utc_time() -> date` | `SELECT utc_time()`
utc_timestamp | `utc_timestamp() -> date` | `SELECT utc_timestamp()`
week | `week(date[mode])  -> integer` | `SELECT week(date('2008-02-20')) FROM my-index LIMIT 1`
weekofyear | `weekofyear(date[mode])  -> integer` | `SELECT weekofyear(date('2008-02-20')) FROM my-index LIMIT 1`
week_of_year\* | `week_of_year(date[mode])  -> integer` | `SELECT week_of_year(date('2008-02-20')) FROM my-index LIMIT 1`
year | `year(date) -> integer` | `SELECT year(date) FROM my-index LIMIT 1`
yearweek\* | `yearweek(date[mode])  -> integer` | `SELECT yearweek(date('2008-02-20')) FROM my-index LIMIT 1`

## String

Function | Specification | Example
:--- | :--- | :---
ascii | `ascii(string T) -> integer` | `SELECT ascii(name.keyword) FROM my-index LIMIT 1`
concat | `concat(str1, str2) -> string` | `SELECT concat('hello', 'world') FROM my-index LIMIT 1`
concat_ws | `concat_ws(separator, string, string…) -> string` | `SELECT concat_ws("-", "Tutorial", "is", "fun!") FROM my-index LIMIT 1`
left | `left(string T, integer) -> T` | `SELECT left('hello', 2) FROM my-index LIMIT 1`
length | `length(string) -> integer` | `SELECT length('hello') FROM my-index LIMIT 1`
locate | `locate(string, string, integer) -> integer` or `locate(string, string) -> INTEGER` | `SELECT locate('o', 'hello') FROM my-index LIMIT 1`, `SELECT locate('l', 'hello', 3) FROM my-index LIMIT 1`
replace | `replace(string T, string, string) -> T` | `SELECT replace('hello', 'l', 'x') FROM my-index LIMIT 1`
right | `right(string T, integer) -> T` | `SELECT right('hello', 1) FROM my-index LIMIT 1`
rtrim | `rtrim(string T) -> T` | `SELECT rtrim(name.keyword) FROM my-index LIMIT 1`
substring | `substring(string T, integer, integer) -> T` | `SELECT substring(name.keyword, 2,5) FROM my-index LIMIT 1`
trim | `trim(string T) -> T` | `SELECT trim('   hello') FROM my-index LIMIT 1`
upper | `upper(string T) -> T` | `SELECT upper('helloworld') FROM my-index LIMIT 1`

## Aggregate

Function | Specification | Example
:--- | :--- | :---
avg | `avg(number T) -> T` | `SELECT avg(2, 3) FROM my-index LIMIT 1`
count | `count(number T) -> T` | `SELECT count(date) FROM my-index LIMIT 1`
min | `min(number T, number) -> T` | `SELECT min(2, 3) FROM my-index LIMIT 1`
show | `show(string T) -> T` | `SHOW TABLES LIKE my-index`

## Advanced

Function | Specification | Example
:--- | :--- | :---
if | `if(boolean, es_type, es_type) -> es_type` | `SELECT if(false, 0, 1) FROM my-index LIMIT 1`, `SELECT if(true, 0, 1) FROM my-index LIMIT 1`
ifnull | `ifnull(es_type, es_type) -> es_type` | `SELECT ifnull('hello', 1) FROM my-index LIMIT 1`, `SELECT ifnull(null, 1) FROM my-index LIMIT 1`
isnull | `isnull(es_type) -> integer` | `SELECT isnull(null) FROM my-index LIMIT 1`, `SELECT isnull(1) FROM my-index LIMIT 1`

## Relevance-based search (full-text search)

These functions are only available in the `WHERE` clause. For their descriptions and usage examples in SQL and PPL, see [Full-text search]({{site.url}}{{site.baseurl}}/search-plugins/sql/full-text/).