Flow control statements in SQL Server

• Begin End

The statement defines a block of SQL code that is typically used in the IF and while statements

Declare @num int ;Set @num=0; while  @num<Tenbegin 　　 Set @num=@num+1; Print 'Hello Word'End

• If Else

Conditional Judgment statement, where else is optional

if  (Selectfrom where name=' Zhang San ') = 1    Print ' the sex of Zhang San is: male ' Else    Print ' the sex of Zhang San is: female '

• While , break, continue

Declare @num int ;Set @num=0; while  @num<Tenbegin 　　 Set @num=@num+1; Print 'Hello Word'    if @num=2        Continue    if @num=5         BreakEnd

Description: This example outputs 5 lines Hello Word

• Goto label (custom tag)

This statement is used to unconditionally transfer the execution order of statements to user-defined lable

Declare @num int;Set @num=0; Echo:Print 'Hello Word'Set @num=@num+1; while  @num<Tenbegin 　　 GotoEchoEnd

• Return

The statement is used to unconditionally exit a query or a procedure

Declare @num int ;Set @num=0; while  @num<Tenbegin 　　 Set @num=@num+1; Print 'Hello Word'    if @num=5        returnEnd

• WAITFOR Delay/time

The statement is used to define a time of day, executing a block of statements. WAITFOR DELAY ' time ' indicates how long it will take to wait, and waitfor when to wait for the moment to execute.

Example: Output ' Hello word ' after 10 seconds

waitfor ' 00:00:10 ' Print ' Hello Word ' -- or Print ' Hello Word ' waitfor ' 00:00:10 '

Example: 12:00 clock output ' Hello word '

waitfor ' 12:00:00 ' Print ' Hello Word ' -- or Print ' Hello Word ' waitfor ' 12:00:00 '

The flow control statements in SQL Server are described here.

Flow control statements in SQL Server