Categories:: Conversion functions

TRY_TO_BOOLEAN¶

A special version of TO_BOOLEAN that performs the same operation (that is, converts an input expression to a Boolean value), but with error-handling support. If the conversion can’t be performed, TRY_TO_BOOLEAN returns a NULL value instead of raising an error.

For more information, see Error-handling conversion functions.

Syntax¶

TRY_TO_BOOLEAN( <string_expr> )

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Arguments¶

string_expr: A string expression that can be evaluated to a BOOLEAN value.

Returns¶

This function returns a value of type BOOLEAN.

Usage notes¶

The input argument must be a string expression. The function evaluates the string expression in the following way:

'true', 't', 'yes', 'y', 'on', '1' return TRUE.
'false', 'f', 'no', 'n', 'off', '0' return FALSE.
All other strings return NULL.

The evaluations of the strings are case-insensitive.

Examples¶

This example uses the TRY_TO_BOOLEAN function:

SELECT TRY_TO_BOOLEAN('True')  AS "T",
       TRY_TO_BOOLEAN('False') AS "F",
       TRY_TO_BOOLEAN('Not valid')  AS "N";

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+------+-------+------+
| T    | F     | N    |
|------+-------+------|
| True | False | NULL |
+------+-------+------+

For more examples, see TO_BOOLEAN.