sql-server - How to select the first row of a set of select statements fast

Question

I have got a bunch of SQL Statements. They are in a special order so if the first statement returns a row I am done, if not go to the next Statement and return the result. What would be a fast way to do this? I tried to realize it in T-SQL because I am on a MSSQL Server but it's really slow.

It's really important to make this thing as fast as possible.

Answer 1

如果您只需要第一行使用TOP 1

SELECT TOP 1 * FROM ...

Answer 2

尝试这样的事情

Select column1 from myTable
if @@ROWCOUNT <> 0 return

Select column1 from myOtherTable
if @@ROWCOUNT <> 0 return

... and so on