sql - How to use BOOLEAN type in SELECT statement

Question

I have a PL/SQL function with BOOLEAN in parameter:

function get_something(name in varchar2, ignore_notfound in boolean);

This function is a part of 3rd party tool, I cannot change this.

I would like to use this function inside a SELECT statement like this:

 select get_something('NAME', TRUE) from dual;

This does not work, I get this exception:

ORA-00904: "TRUE": invalid identifier

As I understand it, keyword TRUE is not recognized.

How can I make this work?

Answer 1

You can definitely get Boolean value from a SELECT query, you just can't use a Boolean data-type.

You can represent a Boolean with 1/0.

CASE WHEN (10 > 0) THEN 1  ELSE 0 END (It can be used in SELECT QUERY)

SELECT CASE WHEN (10 > 0) THEN 1  ELSE 0 END AS MY_BOOLEAN_COLUMN
  FROM DUAL

Returns, 1 (in Hibernate/Mybatis/etc 1 is true). Otherwise, you can get printable Boolean values from a SELECT.

SELECT CASE WHEN (10 > 0) THEN 'true' ELSE 'false' END AS MY_BOOLEAN_COLUMN
 FROM DUAL

This returns the string 'true'.