MYSQL Math operator problem

Background:

In MySQL ' Stringa ' + ' stringb ' This type of operation, inside MySQL will automatically convert to two double number to operate.

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Example:

CREATE TABLE T5 (X varchar (+), Y varchar (32));

INSERT into T5 (x, Y) VALUES (' Hello ', ' 100 ');

Select X + ' y+ ' from T5;

----"Can see the result is not hello200, 100200;

----> If I want to get hello200, 100200; What about the results?

Answer: Using Character handling functions

Select Concat (X, ' n '), concat (Y, ' $ ') from T5;

MYSQL Math operator problem