插入【ZHONGHE_TAB】中的数据 1 USE [SQL- LI] 2 -- 声明3个变量分别用来接收【平均分】,【总分】,【姓名】,和一个控制循环的条件变量@I_WHILE_XUEHAO 3 DECLARE @I_WHILE_XUEHAO INT,@ZONGFEN DECIMAL( 4 , 1 ),@AVGFEN DECIMAL( 3 , 1 ),@XINGMING NVAR
插入【ZHONGHE_TAB】中的数据
1 USE [SQL-LI] 2 --声明3个变量分别用来接收【平均分】,【总分】,【姓名】,和一个控制循环的条件变量@I_WHILE_XUEHAO 3 DECLARE @I_WHILE_XUEHAO INT,@ZONGFEN DECIMAL(4,1),@AVGFEN DECIMAL(3,1),@XINGMING NVARCHAR(10); 4 SELECT @I_WHILE_XUEHAO =6080; 5 --使这个变量【@I_WHILE_XUEHAO】的值指定在【学号】字段上 6 WHILE(@I_WHILE_XUEHAO >=6080 AND @I_WHILE_XUEHAO 6085) 7 BEGIN 8 --求取【平均分】,香港服务器,香港服务器,香港空间,【总分】,【姓名】并存在声明的变量中 9 SELECT @ZONGFEN =(F.语文 +F.数学 +F.英语 ),@AVGFEN =(F.语文 +F.数学 +F.英语 )/3,@XINGMING =X.姓名 10 FROM[DBO].XINXIN_TAB AS X INNER JOIN [DBO].FENSHU_TAB AS F ON X.学号 =F.学号 11 WHERE X.学号 =@I_WHILE_XUEHAO --与【学号同步】 12 --将其变量的数据插入到【ZHONGHE_TAB】的对应字段上 13 INSERT INTO [DBO].ZHONGHE_TAB ([姓名] ,[学号] ,[平均分] ,[总分] ) 14 VALUES(@XINGMING ,@I_WHILE_XUEHAO ,@AVGFEN ,@ZONGFEN ) 15 SELECT @I_WHILE_XUEHAO +=1; --与【学号同步】 16 END 17 GO

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MySQL'sBLOBissuitableforstoringbinarydatawithinarelationaldatabase,whileNoSQLoptionslikeMongoDB,Redis,andCassandraofferflexible,scalablesolutionsforunstructureddata.BLOBissimplerbutcanslowdownperformancewithlargedata;NoSQLprovidesbetterscalabilityand

ToaddauserinMySQL,use:CREATEUSER'username'@'host'IDENTIFIEDBY'password';Here'showtodoitsecurely:1)Choosethehostcarefullytocontrolaccess.2)SetresourcelimitswithoptionslikeMAX_QUERIES_PER_HOUR.3)Usestrong,uniquepasswords.4)EnforceSSL/TLSconnectionswith

ToavoidcommonmistakeswithstringdatatypesinMySQL,understandstringtypenuances,choosetherighttype,andmanageencodingandcollationsettingseffectively.1)UseCHARforfixed-lengthstrings,VARCHARforvariable-length,andTEXT/BLOBforlargerdata.2)Setcorrectcharacters


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