Control-of-Flow Language Usage

Use control-of-flow language with interactive statements, in batches, and in stored procedures.

This table lists the control-of-flow and related keywords and their functions.

Keyword

Function

if

Defines conditional execution.

…else

Defines alternate execution when the if condition is false.

case

Defines conditional expressions using when…then statements instead of if…else.

begin

Beginning of a statement block.

…end

End of a statement block.

while

Repeat performance of statements while condition is true.

break

Exit from the end of the next outermost while loop.

…continue

Restart while loop.

declare

Declare local variables.

goto label

Go to label:, a position in a statement block.

return

Exit unconditionally.

waitfor

Set delay for command execution.

print

Print a user-defined message or local variable on user’s screen.

raiserror

Print a user-defined message or local variable on user’s screen and set a system flag in the global variable @@error.

/* comment */ or --comment

Insert a comment anywhere in a Transact-SQL statement.