可以在游标中循环返回一个结果答案

【问题标题】：can loop in cursor return to one result可以在游标中循环返回一个结果
【发布时间】：2022-08-08 23:07:08
【问题描述】：

我只是用光标练习。我想将所有表合并在一起。我希望你能明白我的目的。

DECLARE @dep NVARCHAR(max) = \'Computer Studies,Civil Engineering\'
declare @tmpTable table (
    Table_Name NVARCHAR(max)
    ,Count int
)
declare cur CURSOR FAST_FORWARD FOR
    SELECT * FROM dbo.DEPARTMENTS  
OPEN cur
FETCH NEXT FROM cur

WHILE @@FETCH_STATUS = 0
BEGIN
    SELECT * FROM dbo.DEPARTMENTS WHERE DepartmentName = @dep
    fetch next from cur
END

CLOSE cur
DEALLOCATE cur

Please do not upload images of code/data/errors when asking a question.a
\"我希望你能明白我的目的。\"并不真地;你什么都不问，通常CURSOR 是编写 SQL 时的错误选择。

标签： sql sql-server

【解决方案1】：

您可以使用临时来累积结果，例如

SET NOCOUNT ON
DECLARE @dep NVARCHAR(max) = 'Computer Studies,Civil Engineering'
declare @tmpTable table (
    Table_Name NVARCHAR(max)
    ,Count int
)
declare cur CURSOR FAST_FORWARD FOR
    SELECT * FROM dbo.DEPARTMENTS  

drop table if exists #results 
select * into #results from dbo.DEPARTMENTS where 1=0
OPEN cur
FETCH NEXT FROM cur

WHILE @@FETCH_STATUS = 0
BEGIN
    INSERT INTO #results
    SELECT * FROM dbo.DEPARTMENTS WHERE DepartmentName = @dep
    fetch next from cur
END

CLOSE cur
DEALLOCATE cur

select * from #results

【讨论】：