How to declare variables in select statement

Please look at this query.

select name form table

Let suppose this returns 100 name records.

I want to store each record in variable and then use this variable in another select

statement.Perhaps I have to do it with inner select but I do not know how.

How this is possible ?

I am working on three complex queries with complex joins I use the code of product and pass them to queries .If first query return the result fine else I move to second query else to third on.I have done this in c# very easily using loops but 开发者_运维知识库it is taking very much time(About 5 minutes for 7000 records) Now I shall store the code in variable and pass it to first query in SQL if count of it result is greater than 0 fine else I move to 2nd else to third one. And so I shall iterate to all productCode Records. `select * from productsale where productname like' %';

Is the a reason you're not using JOIN's? That is usually the best way to use a value in one table to extract values from other tables.

Something like

   select name , dept from name_table nt, dept_table dt
   where nt.name = dt.name

Otherwise you're looking to use cursors. There are a lot of good tutorials on the web, and you may want to find a tutorial specific the DB version you are using.

I hope this helps.