CODEWITHSUNDEEP
mysqlsqlconcatenation
Michel Ayres
Michel Ayres

Reputation: 5985

Update mysql field using CONCAT and SELECT

EDIT

After removing my silly mistake of INTO (I was working with INSERTS and just keep going) the error below is showing. Still not working:

Affected rows: 0

[Err] 1093 - You can't specify target table 'tbl' for update in FROM clause

I'm trying to create an update where I select all the previous data in the column, add a complementary string and save it as new data. The code is below (with the error)

Using only the select, the result:

set @id = 3;

SELECT tbl_alias.string_id 
FROM tbl as tbl_alias
WHERE id = @id

-- the output `3,10,8,9,4,1,7,11,5,2,6,12`

I also tried with this query (the output is what I want)

SELECT CONCAT((
    SELECT tbl_alias.string_id 
    FROM tbl as tbl_alias
    WHERE id = @id
),',13,14,15,16') AS X

-- the output `3,10,8,9,4,1,7,11,5,2,6,12,13,14,15,16`

But after replacing the select below. It brings the same error.

The query

set @id = 3;

UPDATE INTO tbl 
SET string_id = 
    CONCAT((
        SELECT tbl_alias.string_id 
        FROM tbl as tbl_alias
        WHERE id = @id
    ),',13,14,15,16') WHERE id = @id;

The error

[Err] 1064 - 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 ' INTO tbl SET string_id = CONCAT(( SELECT tbl_alias.string_id ' at line 1

It's probably the CONCAT together with SELECT. But I didn't find the solution...

Upvotes: 2

Views: 72013

Answers (3)

Oleksii Kyslytsyn
Oleksii Kyslytsyn

Reputation: 2426

This case helps sometimes to update ALL column data for TESTING purpose: 

UPDATE customer_profile 
  SET businessId = CONCAT(businessId, ' new customer ', (id + 1))

Upvotes: 0

Kickstart
Kickstart

Reputation: 21513

Do you need the sub query?

UPDATE tbl 
SET string_id = CONCAT(string_id, ',13,14,15,16')
WHERE id = @id;

Note that in MySQL you cannot modify using an UPDATE the table that is used in the sub query (although there are fiddles around it):-

https://dev.mysql.com/doc/refman/5.5/en/subqueries.html

In MySQL, you cannot modify a table and select from the same table in a subquery. This applies to statements such as DELETE, INSERT, REPLACE, UPDATE, and (because subqueries can be used in the SET clause) LOAD DATA INFILE.

Upvotes: 25

Nailgun
Nailgun

Reputation: 4169

Try to use UPDATE without INTO:

set @id = 3;

UPDATE tbl 
SET string_id = 
    CONCAT((
        SELECT tbl_alias.string_id 
        FROM tbl as tbl_alias
        WHERE id = @id
    ),',13,14,15,16') WHERE id = @id;

Update:

Try this:

set @id = 3;

UPDATE tbl 
SET string_id = 
    CONCAT(SELECT string_id FROM (
        SELECT tbl_alias.string_id 
        FROM tbl as tbl_alias
        WHERE id = @id
    ) t1 ,',13,14,15,16') WHERE id = @id;

Upvotes: 2

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