当前位置: 首页 > 图文教程 > 数据库 > MSSQL > SQL优化实例:从运行30分钟到运行只要30秒

MSSQL
SQL Server 压缩日志及数据库文件大小
名词解释:带你轻松接触13个数据库术语
自定义数据库自动编号初始值和步进值
合理设置内存让数据库与其他程序共存
SQL Server 2005:数据类型最大值
数据库手边系列:SQL Server数据表信息
SQL Server讲堂:备份和恢复措施
八个有用的WordPress的SQL语句
SQL Server中链接服务器将替代远程服务器
SQLServer与服务器连接时出错的解决方案
在 SQL Server 数据库开发中的十大问题
SQLServer 游标简介与使用说明
SQLServer 存储过程简介与使用方法
数据库大战: MS SQL Server & IBM DB2
如何了解SQL的执行频率
SQL技巧:快速掌握一些异常精妙的"SQL"语句
经验:解决DB2中出现的SQL1032N错误现象
菜鸟课堂:MySQL权限的详细解答
SQL大讲堂:如何了解SQL的执行频率
扫盲大讲堂:SQL查询结果集对注入的影响及利用

MSSQL 中的 SQL优化实例:从运行30分钟到运行只要30秒


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-10-30   浏览: 105 ::
收藏到网摘: n/a

 以下的SQL语句在服务器需要运行长达30分钟才能完成:
SELECT     dbo.ComFlow.ComFlowCode, dbo.ComFlow.ComCode, dbo.ComFlow.CustCode, dbo.ComFlow.DepartCode, dbo.ComFlow.SaleCode,
                      dbo.ComFlow.EmpCode, dbo.ComFlow.Quantity * dbo.Commodity.ConvertRate AS Quantity, CONVERT(datetime, DATENAME(yyyy,
                      dbo.ComFlow.FlowDate) + '-' + DATENAME(mm, dbo.ComFlow.FlowDate) + '-' + DATENAME(dd, dbo.ComFlow.FlowDate)) AS FlowDate,
                      dbo.ComFlow.SalType, dbo.Employee.DepartCode AS DepartIn, dbo.Sale.DepartCode AS DepartOut,
                      dbo.ComFlow.Quantity * dbo.Commodity.TradePrice * dbo.Commodity.Discount / 100 AS Total, dbo.Department.GrpCode AS GrpCodeIn,
                      Department1.GrpCode AS GrpCodeOut
FROM         dbo.ComFlow INNER JOIN
                      dbo.Customer ON
                dbo.ComFlow.SalType IN (N'促销', N'流向退货', N'多级流向') AND dbo.ComFlow.CustCode = dbo.Customer.CustCode
                Or ComFlow_1.SalType IN (N'自然流向', N'自然流向退货') AND ComFlow_1.OutCustCode = Customer_1.CustCode
            INNER JOIN
                      dbo.CustomerRelation ON dbo.ComFlow.ComCode = dbo.CustomerRelation.ComCode AND
                      dbo.CustomerRelation.CustCode = dbo.Customer.CustCode INNER JOIN
                      dbo.Employee ON dbo.CustomerRelation.EmpCode = dbo.Employee.EmpCode INNER JOIN
                      dbo.Sale ON dbo.ComFlow.SaleCode = dbo.Sale.SaleCode INNER JOIN
                      dbo.Department ON dbo.Department.DepartCode = dbo.Employee.DepartCode INNER JOIN
                      dbo.Department AS Department1 ON Department1.DepartCode = dbo.Sale.DepartCode AND
                      dbo.Department.GrpCode <> Department1.GrpCode INNER JOIN
                      dbo.Commodity ON dbo.ComFlow.ComCode = dbo.Commodity.ComCode
WHERE     (NOT (dbo.ComFlow.SalType = N'流向退货')) OR
                      (NOT (dbo.Customer.Type = N'医药公司'))
虽然说,我们使用这个语句的应用是一个BI应用,实时性要求不高,但是,我觉得没有道理会运行这么久,应该有办法优