MySQL - 一次向所有查询添加常见的WHERE条件。

Question

I have set of sql queries already written and working fine in my website.

Now, i want to add 'where common condition clause' all of those queries. I don't wanna re write all my queries with this additional condition, instead i like do something by which it automatically applies to all queries run on my database from now on.

Is there any such method to do this?

MY Data base: MYSQL

MY website: PHP, YII

Answer 1

There may be a way to solve this problem using views. Say you have queries of the form:

select . . .
from table1 t1 . . .

And you now want:

select . . .
from table1 t1 . . .
where t1.field = 'x'

You can solve this by doing the following steps:

1. Rename table1 to something (say _table1):

   rename table table1 to _table1;
   

2. Create a view with the name table1:

   create view table1 as
   select *
   from _table1
   where field = 'x';
   

In general, I think it is a better idea to change existing queries (and views in MySQL can cause problems with optimization). However, there are some circumstances where this approach might be appropriate for quickly getting the changes you need.