Type Conversions

Converting from one data type to another can be done using CAST or TRY_CAST.

CAST (<expression> AS <type>)
<expression>::<type>
TRY_CAST (<expression> AS <type>)

The SQL CAST function converts a value from one type to another. If the type conversion fails, an error will be thrown. In contrast, the TRY_CAST function returns NULL if the conversion fails. The syntax :: is equivalent CAST.

Examples:

SELECT CAST('true' AS bool);
Result: t

SELECT CAST('tuu' AS bool);
Result: (error)

SELECT 'true'::bool;
Result: t

SELECT 'tuu'::bool;
Result: (error)

SELECT TRY_CAST('true' AS bool);
Result: t

SELECT TRY_CAST('tuu' AS bool);
Result: NULL