我如何在没有加入的情况下优化这个存储过程

Posted 2023-04-14

【中文标题】我如何在没有加入的情况下优化这个存储过程

【英文标题】：How can i optimize this stored procedure Without Join

【发布时间】：2013-10-28 13:57:01

【问题描述】：

我在即时搜索时遇到了这样的情况，但这个查询有更多的 NOT IN 检查

ALTER PROC [dbo].[DPR_SP_GetEmployeeDetailsByKeyword]
@keyword varchar(10),
@hotelId int
AS
BEGIN
SELECT  EmployeeDetails.EmployeeId,EmployeeDetails.SageEmployeeId,EmployeeDetails.FirstName,EmployeeDetails.LastName
FROM    EmployeeDetails
WHERE   (EmployeeDetails.EmployeeId NOT IN (    SELECT  EmployeeWorksIn.EmployeeId
                                                FROM    EmployeeWorksIn
                                                WHERE   EmployeeWorksIn.HotelId=@hotelId
                                                )
AND
        EmployeeDetails.EmployeeId LIKE @keyword+'%')
        OR
        (EmployeeDetails.EmployeeId NOT IN (    SELECT  EmployeeWorksIn.EmployeeId
                                                FROM    EmployeeWorksIn
                                                WHERE   EmployeeWorksIn.HotelId=@hotelId
                                                )
        AND
OR 
        (EmployeeDetails.EmployeeId NOT IN (    SELECT  EmployeeWorksIn.EmployeeId
                                                FROM    EmployeeWorksIn
                                                WHERE   EmployeeWorksIn.HotelId=@hotelId
                                                )
        AND
        EmployeeDetails.DateOfBirth LIKE @keyword+'%')

如何优化这个查询

谢谢

【问题讨论】：

当你分析这个时，瓶颈在哪里？使用 SQL Management Studio，您可以查看执行计划以确定这一点。

【参考方案1】：

你可以把它改写成

alter proc dbo.DPR_SP_GetEmployeeDetailsByKeyword 
    @keyword varchar(10),
    @hotelId int
As
Select
    e.EmployeeId,
    e.SageEmployeeId,
    e.FirstName,
    e.LastName
From
    EmployeeDetails e
        Left Outer Join
    EmployeeWorksIn w
        on e.EmployeeId = w.EmployeeId and w.HotelId = @hotelId
Where
    w.EmployeeID Is Null And (
        e.EmployeeId Like @keyword+'%' Or
        e.Something Like @keyword+'%' Or -- appears to be missing from question
        e.DateOfBirth Like @keyword+'%'
    );

之后，您将研究索引以加快速度。