sql-Defining variables

Declare @subject nvarchar Set @subject = (select subject from dbo. Scores where id=1)

　　

--select @subject =subject from dbo. Scores where id=1--a scalar scalar is a single value, and if it is a result set, the final value of the set is the last value in the result set, select @subject Set the self-increment

INSERT INTO dbo. Student values (' Harry ', ' Male ', ' Max '); select @ @IDENTITY;   INSERT INTO dbo. Student output inserted.id values (' Li Liu ', ' Male ', 41)

　　

Execution of certain scripts requires consideration of the behavior of the judgment loop, so there is an if and other struct if () {}------------>sqlserver is the IF () Begin end

    declare @name nvarchar (50) = ' Harry '  if (@name = ' Harry ')  begin    Select ' True '  end  else  begin  Select ' False '  

　　

Cycle-Calculates the 1-100 and

  declare @int int=1;  declare @total int=0;  while (@int <=100)  begin  set @[email protected][email protected];  Set @[email protected] +1;  End  Select @total

　　

sql-Defining variables