存储过程中的 SQL Server 变量范围

Question

我想在 SQL Server 存储过程的 if/else 语句中声明一个变量。我知道这是相当不可能的，因为 SQL Server 不会对过程中的变量声明进行内存管理。有没有办法在 if/else 语句中定义一个变量的作用域，然后在另一个 if/else 语句中重新声明具有相同名称的变量？例如:

create procedure Foo
as
begin  
    if exists (x)
    begin
        declare @bob int
        set bob = 1
    end
    else
    begin
        declare @bob int
        set bob = 2
    end
end

Answer 1

来自books online :

The scope of a variable is the range of Transact-SQL statements that can reference the variable. The scope of a variable lasts from the point it is declared until the end of the batch or stored procedure in which it is declared.

但是。没有什么可以阻止你这样做:

create procedure Foo as begin

declare @bob int

if exists (x)
begin
    set @bob = 1
end
else
begin
    set @bob = 2
end

end