使用MYSQL上每个值的条件更新具有相同列名的多个表

Question

I've a column "pid" and a lot of table on each database , then I want to update all table from every database with column "pid" and set 'pid' = 5 where 'pid' = 3 and set 'pid' = 6 where 'pid = '7' on 1 query .

I've find post like this and try to apply it:

Select 'UPDATE ' + TABLE_NAME + ' SET pid = ''5'' '
From INFORMATION_SCHEMA.COLUMNS 
WHERE COLUMN_NAME = 'pid'

Without condition for try it , then MYSQL just return me a select with value 0 .

'UPDATE ' + TABLE_NAME + ' SET pid = ''5'' '
                                           0

Need a little help and explain for make this query work and understand how its work .

Really thanks everyone :)

Answer 1

UPDATE table_name
SET pid = 5
WHERE pid = 3;

It should be implemented like this. You simply tell to update the table named table_name to set pid as ' 5 ' wherever it finds it as ' 3 '.

Read also here . ;)