如何在 MySQL LIKE 子句中使用用户变量？

Question

I am trying to setup a few simple SQL scripts to help with some short term DB administration. As such, I'm setting up variables to try to make it easier to reuse these scripts.

The problem I'm having is specifically with the LIKE clause.

SET @email = 'test@test.com';

SELECT email from `user` WHERE email LIKE '%@email%';

So I want to have it finding results based on the email SET in the variable. The query works if I manually enter the email into the LIKE clause.

How can I get the LIKE clause to work with the user variable?

UPDATE: @dems's answer works for this simple case, but I'm having trouble with a more complex query.

SET @email = 'test@test.com';

SELECT project.projectno, project.projectname, login.username, 
CONCAT(login.firstname, ' ', login.lastname), projectuser.title 
FROM projectuser 
INNER JOIN login ON projectuser.uid = login.uid 
LEFT JOIN project ON projectuser.pid = project.pid
WHERE login.username LIKE CONCAT ('%', @email, '%')

Gives me the error "FUNCTION mydb.CONCAT does not exist"

The query works without the CONCAT():

SET @email = 'test@test.com';

SELECT project.projectno, project.projectname, login.username, 
CONCAT(login.firstname, ' ', login.lastname), projectuser.title 
FROM projectuser 
INNER JOIN login ON projectuser.uid = login.uid 
LEFT JOIN project ON projectuser.pid = project.pid
WHERE login.username LIKE @email

Answer 1

SET @email = 'test@test.com';

SELECT email from `user` WHERE email LIKE CONCAT('%', @email, '%');

Answer 2

Works without concat():

LIKE '%{$var}%'

(Mysql version 5.+)

Answer 3

No need to CONCAT just use '%'+ Variable +'%':

SET @email = 'test@test.com';
SELECT email from `user` WHERE email LIKE '%' + @email + '%';

Answer 4

使用与oracle相同的语法似乎可行：

SELECT email from user WHERE email LIKE '%' || @email || '%';

Answer 5

You may have error

Error Code: 1267. Illegal mix of collations for operation 'like'    0.016 sec

In this case you need to specify the same collation as used for your table like that:

SET @email = 'test@test.com' COLLATE utf8_unicode_ci;

Answer 6

I resolved using the CONCAT function before using LIKE statement:

SET @email = 'test@test.com';
set @email = CONCAT('%',@email,'%');
SELECT email from `user` WHERE email LIKE @email;

It works fine for me

Answer 7

BEGIN 
    SET @emailid = CONCAT('%', 'email@email.com' ,'%');
    SET @t1 =CONCAT('SELECT * FROM user WHERE email LIKE ''', @emailid, '''');
    PREPARE stmt3 FROM @t1;
    EXECUTE stmt3;
    DEALLOCATE PREPARE stmt3;
END

Answer 8

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