What is the sequence of execution of AND statements?

1

Hello

If a statement has the following criteria:

WHERE [1] NOT IN ('a','b','c')
AND CASE WHEN [1] IS 'a' THEN [2] ELSE [1] END <> 'b'

How will SQL process this? Will it do the first filtering and then the CASE?

Thanks!

2

SQL can do independent clauses like that in whatever order it chooses to do them.

If you want to enforce an order, you can embed all of it in a CASE statement; CASE statements are always evaluated in order.

For example, if you write:

WHERE <condition_1> AND <condition_2> AND <condition_3>

then SQL can evaluate either cond_1 or _2 or _3 first, and any of the others next, as SQL decides is best.