About the LTRIM cannot remove with: field-CodePudding

Example:
MAIL:[email protected]

SELECT LTRIM (' MAIL:[email protected] ', 'MAIL:') FROM DUAL;

Results: [email protected]

Why didn't LI, could you tell me the reason why

CodePudding user response:

The

refer to the original poster jack_qd response:

, for example:
MAIL:[email protected]

SELECT LTRIM (' MAIL:[email protected] ', 'MAIL:') FROM DUAL;

Results: [email protected]

Why didn't LI, could you tell me the reason why

The original poster is likely to understand the mechanism of LTRIM is a little problem, then find some books to see, or, you can change the original string:
SELECT LTRIM (' MAIL:[email protected] ', 'MAIL:') FROM DUAL;
So, may be more clear,