Conditional Functions

`coalesce`

Returns the first non-null value in the argument list. Like a CASE expression, arguments are only evaluated if necessary. Examples:

examples.sql

CREATE TABLE tbl as VALUES ('1', null), ('2', '2'), (null, '3');
SELECT 
    COALESCE(column1, column2) as value
FROM tbl;
 -- value '('1', '2', '3')'

Supported Signatures

function coalesce($1, ...) returns $1

🔗 Official Documentation

`if`

Evaluates expression parameter and returns second if condition is true, otherwise null is returned and true_value is not evaluated. Examples:

examples.sql

SELECT IF(2 > 1, 'HIGHER', 'LOWER') AS value; -- value 'HIGHER'

Supported Signatures

function if(boolean, $1, $1) returns $1

🔗 Official Documentation

`nullif`

Returns null if value1 equals value2, otherwise returns value1. Examples:

examples.sql

SELECT nullif(1, 1) AS value; -- value 'NULL'
SELECT nullif(2, 1) AS value; -- value '2'

Supported Signatures

function nullif($1, $1) returns $1

🔗 Official Documentation

Binary Functions Array Functions

SDF DB

Trino Supported Functions

Conditional Functions

`coalesce`

`if`

`nullif`

​coalesce

​if

​nullif

`coalesce`

`if`

`nullif`