CAST

All functions > CORE > CAST

Returns the given expression casted to the given type, or raise an exception if the conversion fails.

Signatures

Returns: The expression converted to the specified type

CAST(expr: T, as_type: DataTypeEnum.TYPE) → U

Notes

• Converts a value from one data type to another
• Supports conversions between numeric types (BIGINT, DECIMAL, DOUBLE)
• Supports conversions between numeric and string types (VARCHAR)
• Special handling for ROW and ARRAY types
• Conversion may fail if the value cannot be represented in the target type
• For safe casting that returns NULL on failure, use TRY_CAST
• NULL values remain NULL after casting
• Precision may be lost when converting between numeric types
• Follows SQL standard casting rules

Examples

SELECT
    f1 := CAST(42 AS DOUBLE),  -- Integer to double
    f2 := CAST(3.14e0 AS BIGINT),  -- Double to integer (truncates)
    f3 := CAST('123' AS BIGINT),  -- String to integer
    f4 := CAST(42 AS VARCHAR),  -- Integer to string
    f5 := CAST(3.14 AS VARCHAR),  -- Decimal to string
    f6 := CAST('2024-01-15' AS DATE)  -- String to date
;