MYSQL从一个表查询SELECT并将结果与​​另一表联接

Question

I have two tables MESSAGES and USERS :

MESSAGES :

|id|user_id|message|1st number|2nd number|

USERS :

|user_id|name|

I'm trying to display a message and by user_id get username next to the message. Is it possible to do it in just one query?

At this moment my demo query looks like that but it does not work.

SELECT *
 FROM   messages
 WHERE  1st number BETWEEN $x AND $z
 AND 2nd BETWEEN $x AND $z
 LEFT JOIN users
 ON users.user_id= messages.user_id
 ORDER BY time DESC

The error which I get: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'LEFT JOIN users ON WHERE users.user_id= messages.user_id ORDER BY time DESC' at line 5

Answer 1

There are a few problems with your SQL:

• if a column name contains spaces, you need to quote them
• you need to write the full column names in mysql
• JOIN comes before WHERE

So something like

SELECT *
FROM messages
 LEFT JOIN users ON users.user_id=messages.user_id
WHERE `1st number` BETWEEN $x AND $z
 AND `2nd number` BETWEEN $x AND $z
ORDER BY time DESC

should work

Answer 2

Please try this.

SELECT
    *
FROM
    messages
    LEFT JOIN users ON users.user_id = messages.user_id
WHERE
        `1st number` BETWEEN $x AND $z
    AND
        `2nd number` BETWEEN $x AND $z
ORDER BY time DESC