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This judgment as long as it is used for substring_index (),

 
Select 
Substring_index (a_name, '|', 1) as m 
Substring_index (a_name, '|', 1) as n 
The from 
TableA 

So write, if can't find '|' m and n are returned is a_name
Expectations are m return a_name, n return is empty (" "),
Think of way is to add a judgment, but can't try for a long time, come to a big,

CodePudding user response:

Should use INSTR function, INSTR has two parameters, using the method about the following:
INSTR (A, B), if A consists of B, back in the position of A B, if A does not contain B, returns 0,
Sample:
SELECT INSTR (' 123 | ', '|'), INSTR (' 123 ', '|');
What you need is something like this:
SELECT the IF (INSTR (' 123 | ', '|')=0, 1), the IF (INSTR (' 123 ', '|')=0, 1);
Or, the following three lines to perform together,
The SET @ A:='123 |';
SET @ : B='123';
SELECT the IF (INSTR (@ A, '|')=0, 1), the IF (INSTR (@ B, '|')=0, 1);

CodePudding user response:

Expectations are m return a_name, n return is empty (" ")
What is this requirement, whether to contain |,

CodePudding user response:

Select a case when a_name like '% % |' then one else a_name end
The from tableA