大神解说sql

A. 刚学sql数据库就怎么那么复杂的例子看不懂求大神解释

请参阅下面的文章，主要是讲述如何使用命令创建数据库,

在sql命令有指定文件路径 文件组 大小

使用sql脚本创建数据库

如果有疑问，请及时沟通

请采纳！

B. 一段很复杂很复杂的SQL语句。。求大神解释。。。

Select
	*
From
	(
	Select
		*
	From
		(
		Select
			Number
			,ChineseName
			,tb1.DepartmentCode
			,DepartmentName
			,ShiftId
			,ShiftName
			,Degree
			,AskForLeaveType
			,WorkOnDate
			,OnDutyType
			,StartTime
			,EndTime
			,AOnDuty
			,AOffDuty
			,Allday
			,tb1.SumTotal
			,'Error'=
					Case
						WhenDegree=1ANDStartTime<=AOnDutyANDEndTime<=AOnDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=1ANDStartTime>=AOffDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=1ANDStartTime>=WorkOnDate+''+'12:30'ANDEndTime<=WorkOnDate+''+'13:30'ANDCharindex('常白班',ShiftName)>0ANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=2ANDStartTime<=AOnDutyANDEndTime<=AOnDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=2ANDStartTime>=AOffDutyANDEndTime<=BOnDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=2ANDStartTime>=BOffDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=3ANDStartTime<=AOnDutyANDEndTime<=AOnDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=3ANDStartTime>=AOffDutyANDEndTime<=BOnDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=3ANDStartTime>=BOffDutyANDEndTime<=COnDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenDegree=3ANDStartTime>=COffDutyANDShiftId>0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenShiftId=0ANDLeft(AskForLeaveType,1)='0'Then0
						WhenShiftId>0ANDLeft(AskForLeaveType,1)<>'0'ANDLeft(OnDutyType,1)=0Then0
						WhenShiftId>0ANDLeft(AskForLeaveType,1)<>'0'ANDLeft(OnDutyType,1)=2ANDAskForLeaveType='出差假'Then0
						WhenShiftId>0ANDLeft(AskForLeaveType,1)<>'0'ANDLeft(OnDutyType,1)=2ANDAskForLeaveType='产假'Then0
						WhenShiftId=0ANDLeft(AskForLeaveType,1)<>'0'ANDConvert(varchar(10),StartTime,108)='00:00:00'ANDConvert(varchar(10),EndTime,108)='00:30:00'Then0
					Else
						1
					End
		From
			(
			Select
				Number
				,ChineseName
				,DepartmentName
				,d.DepartmentCode
				,p.ShiftId
				,p.ShiftName
				,Degree
				,AskForLeaveType
				,Convert(varchar(10),WorkOnDate,120)as'WorkOnDate'
				,StartTime
				,EndTime
				,AllDay
				,SumTotal
				,CaseWhenRight(Convert(Varchar(10),WorkOnDate,120),5)IN(selectRight(Convert(Varchar(10),HolidayDate,120),5)FromAttendanceHoliday)THEN'2-公众假上班'ELSE'0-平时上班'ENDAS'OnDutyType'
				,CaseWhenLeft(FristBrushDate,1)='1'ANDConvert(varchar(10),AOffDuty,120)>Convert(varchar(10),AOnDuty,120)ThenCAST(Convert(Varchar(11),Dateadd(dd,-1,OnDutyDate),120)+Convert(Varchar(5),AOnDuty,108)ASDateTime)ELSECAST(Convert(Varchar(11),OnDutyDate,120)+Convert(Varchar(5),AOnDuty,108)ASDateTime)EndAS'AOnDuty'
				,CaseWhenLeft(FristBrushDate,1)='0'ANDConvert(varchar(10),AOnDuty,120)<Convert(varchar(10),AOffDuty,120)ThenCAST(Convert(Varchar(11),Dateadd(dd,1,OnDutyDate),120)+Convert(Varchar(5),AOffDuty,108)ASDateTime)ELSECAST(Convert(Varchar(11),OnDutyDate,120)+Convert(Varchar(5),AOffDuty,108)ASDateTime)EndAS'AOffDuty'
				,CAST(Convert(Varchar(11),OnDutyDate,120)+Convert(Varchar(5),BOnDuty,108)ASDateTime)AS'BOnDuty'
				,CAST(Convert(Varchar(11),OnDutyDate,120)+Convert(Varchar(5),BOffDuty,108)ASDateTime)AS'BOffDuty'
				,CAST(Convert(Varchar(11),OnDutyDate,120)+Convert(Varchar(5),COnDuty,108)ASDateTime)AS'COnDuty'
				,CAST(Convert(Varchar(11),OnDutyDate,120)+Convert(Varchar(5),COffDuty,108)ASDateTime)AS'COffDuty'
			From
				.DepartmentCode=d.DepartmentCode
				.Employeeid=a.Employeeid
				INNERJOINAttendanceSpellpona.Employeeid=p.Employeeidanda.WorkOndate=p.OnDutyDate
				LEFTJOINAttendanceShiftssonp.Shiftid=s.Shiftid
			)tb1
		)tb2WhereError=1

		UNIONALL

		Select
			Number
			,ChineseName
			,DepartmentCode
			,DepartmentName
			,ShiftId
			,ShiftName
			,Degree
			,AskForLeaveType
			,WorkOnDate
			,CaseWhenRight(Convert(Varchar(10),WorkOnDate,120),5)IN(selectRight(Convert(Varchar(10),HolidayDate,120),5)fromAttendanceHoliday)THEN'2-公众假上班'ELSE'0-平时上班'ENDAS'OnDutyType'
			,StartTime
			,EndTime
			,AOnDuty
			,AOffDuty
			,Allday
			,SumTotal
			,Error
		From
			(
			Select
				Number
				,ChineseName
				,d.DepartmentCode
				,DepartmentName
				,p.ShiftId
				,p.ShiftName
				,Degree
				,AskForLeaveType
				,WorkOnDate
				,StartTime
				,EndTime
				,Sumtotal
				,NULLAS'AOnDuty'
				,NULLAS'AOffDuty'
				,AllDay
				,1AS'Error'
			From
				AttendanceAskForLeavea
				LEFTJOINEmployeeseONa.Employeeid=e.Employeeid
				LEFTJOINDepartmentsdONe.DepartmentCode=d.DepartmentCode
				LEFTJOINAttendanceSpellpONa.Employeeid=p.EmployeeidANDa.WorkOnDate=p.OnDutyDate
				LEFTJOINAttendanceShiftssONp.ShiftId=s.ShiftId
			Where
				Left(IncumbencyStatus,1)<>1
			Groupby
				Number,ChineseName,d.DepartmentCode,DepartmentName,p.ShiftId,p.ShiftName,Degree,AskForLeaveType,AllDay,WorkOnDate,StartTime,EndTime,Sumtotal
			having
				Count(1)>1
			)tb3
		)tb4

对你的代码格式化后发现，还缺少一些语句，你是否粘贴完整了？

读完SQL语句后发现，其实是一个考勤核算的查询语句，是两个大的SQL查询Union ALL的结果