If Else conditions SQL/MSDN

The IF-ELSE condition is used to perform a task based on certain conditions. The structure of the IF-ELSE loop is:


IF (condition)
begin
        do this
        do this
        etc...
end

Explanations:
conditions: it can be any condition that can compare statements, variables, constant, etc using Boolean functions .

do this: it can be any execution process like the Update Statements, Alter Statements, etc.

See

Here

for more example