Question

有人可以解释为什么在示例中

DECLARE @compareprice money, @cost money 
EXECUTE Production.uspGetList '%Bikes%', 700, 
    @compareprice OUT, 
    @cost OUTPUT
IF @cost <= @compareprice 
BEGIN
    PRINT 'These products can be purchased for less than 
    $'+RTRIM(CAST(@compareprice AS varchar(20)))+'.'
END
ELSE
    PRINT 'The prices for all products in this category exceed 
    $'+ RTRIM(CAST(@compareprice AS varchar(20)))+'.'

https://msdn.microsoft.com/en-us/library/ms182717.aspx上的

有一个BEGIN和END封闭了IF块，但不是ELSE块？

Answer 1

当只有一个语句时，

BEGIN和END是可选的。在此示例中，IF或ELSE子句中不需要它们，因为只有一个语句。它可以这样写：

IF @cost <= @compareprice 
    PRINT 'These products can be purchased for less than 
    $'+RTRIM(CAST(@compareprice AS varchar(20)))+'.'
ELSE
    PRINT 'The prices for all products in this category exceed 
    $'+ RTRIM(CAST(@compareprice AS varchar(20)))+'.'

为什么IF子句中有BEGIN和END而不是ELSE子句？

1 个答案: