[HACKERS] Differences in WHERE clause of SELECT

[Prabakaran, Vaishnavi]

Hi,

 

I am a newbie to PostgreSQL and was wondering about the following
behaviour.

 

 

SELECT true WHERE 1 = '1';     <-- Returns true 

 

SELECT true WHERE 1 BETWEEN '0' and '2';    <-- Returns true

 

SELECT true WHERE 1 IS DISTINCT FROM '2';    <-- Returns true

 

SELECT true WHERE 1 LIKE '1';   <-- Returns 'operator does not exist'
Error

 

SELECT true WHERE '1' LIKE 1;   <-- Returns 'operator does not exist'
Error

 

 

 

The first three queries work because of the implicit cast whereas the
'LIKE' is not using implicit cast. 

 

Can you please help me understand why 'LIKE' does not use implicit cast
? 

 

 

 

Best Regards,

Vaishnavi