CAST function and operator

The cast function and operator return a value converted to the specified type.

Signatures

{{% include-syntax file="examples/sql_functions/cast" example="syntax-function" %}}

{{% include-syntax file="examples/sql_functions/cast" example="syntax-operator" %}}

The following special syntax is permitted if val is a string literal:

{{% include-syntax file="examples/sql_functions/cast" example="syntax-literal" %}}

Return value

cast returns the value with the type specified by the type parameter.

Details

Valid casts

Cast context defines when casts may occur.

Casts allowed in less strict contexts are also allowed in stricter contexts. That is, implicit casts also occur by assignment, and both implicit casts and casts by assignment can be explicitly invoked.

¹ Arrays and lists are composite types subject to special constraints. See their respective type documentation for details.

² Casting a float to a numeric can yield an imprecise result due to the floating point arithmetic involved in the conversion.

Examples

SELECT INT '4';

 ?column?
----------
         4

SELECT CAST (CAST (100.21 AS numeric(10, 2)) AS float) AS dec_to_float;

 dec_to_float
--------------
       100.21

SELECT 100.21::numeric(10, 2)::float AS dec_to_float;

 dec_to_float
--------------
       100.21

Related topics

• Data Types