Use
control-of-flow language with interactive statements, in batches,
and in stored procedures. Table 14-1 lists the control-of-flow and related
keywords and their functions.
Table 14-1: Control-of-flow and related keywords
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.
|
