Mysql in PHP - how to update only one row in table but with greatest id number

UPDATE table_NAME
SET COLUMN_NAME='COLUMN_VALUE' 
ORDER BY ID 
DESC LIMIT 1;

Because you can't use SELECT IN DELETE OR UPDATE CLAUSE.ORDER BY ID DESC LIMIT 1. This gives you ID's which have maximum value MAX(ID) like you tried to do. But MAX(ID) will not work.


I think iblue's method is probably your best bet; but another solution might be to set the result as a variable, then use that variable in your UPDATE statement.

SET @max = (SELECT max(`id`) FROM `table`);
UPDATE `table` SET `name` = "FOO" WHERE `id` = @max;

This could come in handy if you're expecting to be running multiple queries with the same ID, but its not really ideal to run two queries if you're only performing one update operation.


UPDATE table SET name='test_name' WHERE id = (SELECT max(id) FROM table) 

This query will return an error as you can not do a SELECT subquery from the same table you're updating.

Try using this:

UPDATE table SET name='test_name' WHERE id = (
    SELECT uid FROM (
        SELECT MAX(id) FROM table AS t
    ) AS tmp
)

This creates a temporary table, which allows using same table for UPDATE and SELECT, but at the cost of performance.


The use of MAX() is not possible at this position. But you can do this:

UPDATE table SET name='test_name' ORDER BY id DESC LIMIT 1;

For multiple table, as @Euthyphro question, use table.column.
The error indicates that column id is ambiguous.

Example :

UPDATE table1 as t1
LEFT JOIN table2 as t2
       ON t2.id = t1.colref_t2
SET t1.name = nameref_t2
ORDER BY t1.id DESC
LIMIT 1

Tags:

Mysql

Php

Max