Question

I have three table.2 data comes from 2 table and insert it into another table.
Let: tbl_id hold the field id and tbl_msg hold the field msg.

tbl_id               tbl_msg

id                   msg
------               --------
1234                 test_msg
5678
9876

Now my desired output should be in tbl_info

id    msg
---   -------
1234  test_msg
5678  test_msg
9876  test_msg

I write a query but its showing error that: Subquery returns more than 1 row.
My query is below:

INSERT INTO tbl_info (id,msg) VALUES((SELECT id FROM tbl_id),(SELECT msg FROM tbl_msg))

Answer 1

You need to write a single SELECT statement which returns teh rows exactly as you want them inserted.

The 2 inner selects you have return all the id’s from tbl_id and all the msg from tbl_msg, which doesn’t make much sense.

First write the select, e.g.:

SELECT tbl_id.id, tbl_msg.msg 
FROM tbl_id
JOIN tbl_msg ON tbl_id.fk = tbl_msg.fk
WHERE (...)

Then use it for the INSERT:

INSERT INTO tbl_info (id, msg)
SELECT tbl_id.id, tbl_msg.msg 
FROM tbl_id
JOIN tbl_msg ON tbl_id.fk = tbl_msg.fk
WHERE (...)

---

UPDATE according to OP’s comments:

INSERT INTO tbl_info (id, msg)
 SELECT tbl_id.id, single_msg.msg 
 FROM tbl_id
 JOIN (SELECT msg 
      FROM tbl_msg 
      WHERE CURDATE()=DATE_FORMAT(date_time,'%Y-%m-%d') 
      ORDER BY date_time DESC LIMIT 1) as single_msg ON 1=1;

This will not be very efficient because the inner select will be executed for each record in tbl_id. A more efficient solution may be:

SELECT msg INTO @msg
FROM tbl_msg 
WHERE CURDATE()=DATE_FORMAT(date_time,'%Y-%m-%d') 
ORDER BY date_time DESC LIMIT 1;

INSERT INTO tbl_info (id, msg)
    SELECT tbl_id.id, @msg 
    FROM tbl_id;