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notes/数据库系统原理.md
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@ -216,23 +216,23 @@ MySQL InnoDB 采用的是两阶段锁协议。在事务执行过程中，随时
**分解前**
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?S(Sno,Cname,Sname,Sdept,Mname)"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?S(Sno,Cname,Sname,Sdept,Mname)"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sno,Cname->Sname,Sdept,Mname"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sno,Cname->Sname,Sdept,Mname"/></div> <br>
**分解后**
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?S1(Sno,Sname,Sdept,Mname)"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?S1(Sno,Sname,Sdept,Mname)"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sno->Sname,Sdept,Mname"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sno->Sname,Sdept,Mname"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sdept->Mname"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sdept->Mname"/></div> <br>
<div align="center"> <img src="../pics//8ef22836-8800-4765-b4b8-ade80096b323.jpg"/> </div><br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?S2(Sno,Cname,Grade)"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?S2(Sno,Cname,Grade)"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sno,Cname->Grade"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sno,Cname->Grade"/></div> <br>
<div align="center"> <img src="../pics//b0748916-1acd-4138-b24c-69326cb452fe.jpg"/> </div><br>
@ -250,15 +250,15 @@ MySQL InnoDB 采用的是两阶段锁协议。在事务执行过程中，随时
关系模式 STC(Sname, Tname, Cname, Grade)，其中四个属性分别为学生姓名、教师姓名、课程名和成绩。有以下函数依赖：
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Cname->Tname"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Cname->Tname"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Cname->Grade"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Cname->Grade"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Tname->Cname"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Tname->Cname"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Tname->Grade"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Sname,Tname->Grade"/></div> <br>
<div align="center"> <div align="center"><img src="https://latex.codecogs.com/gif.latex?Tname->Cname"/></div> <br> </div><br>
<div align="center"><img src="https://latex.codecogs.com/gif.latex?Tname->Cname"/></div> <br>
分解成 SC(Sname, Cname, Grade) 和 ST(Sname, Tname)，对于 ST，属性之间是多对多关系，无函数依赖。