5.1ڶͬʱѧϢѧΪ
	Create  table  student
	(sID  char(6)  primark key,    
	sName  varchar(20)  
	)
5.2УѧϰɼѧźͿγ̺Ϊʹ´
	Create  table  grade
	(sID char(6) ,    
	kcID char(6),
	gradenum smallint
	constraint pk_num primary key (sID,kcID) )
5.3Ѵڵı罫ʦϢнʦΪʹô£
	ALTER  table  teacher 
	ADD
	CONSTRAINT PK_NUM  PRIMARY KEY (tID)
5.4ڶͬʱΨһԼѧϢϵ绰ΪΨһԼУʹô£
	Create  table  student
	(sID  char(6)  primark key,    
	sTel varchar(20) unique )
5.5Ѵڵı罫ԺϵϢԺϵΪΨһԼУʹô£
	ALTER  table  college
	ADD
	CONSTRAINT U_col_name  UNIQUE (colName)
5.6ڶͬʱĬԼѧϢԱĬֵΪСʹô£
	Create  table  student
	(sID  char(6)  primark key,    
	sSex char(2)  default С,
	)
5.7ѴڵıĬֵ罫ʦϢнʦԱĬֵΪСʹô£
	ALTER  table  teacher
	ADD
	CONSTRAINT  DEF_tsex  DEFAULT С  FOR (tsex)
5.8ڶͬʱüԼѧϰɼгɼеȡֵΧΪ0-100ʹô£
	Create  table  grade
	(gradenum  smallint  check (gradenum >0 and gradenum <100),
	)
5.9ѴڵıӼԼѧϢѧԱȡֵֻΪСŮʹô£
	ALTER  table  student
	ADD
	CONSTRAINT  CK_sSex  CHECK(sSex =С  or  sSex=Ů )
5.10ڶͬʱÿԼѧϢѧΪգڿȡֵʹô£
	Create  table  student
	(sName  varchar (20)  not null ,
	sBirthday smalldatetime null,
	)
5.11ڶͬʱԼʹôʵ£
	Create  table  grade
	(sID  char(6)  references  student(sID),
	)
5.12ѴڵıԼʹôʵ£
	ALTER  table  grade
	ADD
	CONSTRAINT  FK_SID  FOREIGN KEY (sID) REFERENCES student (sID)
5.13ӼԼʱѴݽԼ 
	ALTER  table  student
	WITH  NOCHECK 
	ADD
	CONSTRAINT  CK_sSex  CHECK(sSex =С  or  sSex=Ů )
5.14ʹļԼЧʹ´ʵ
	ALTER  table  student
	NOCHECK 
	CONSTRAINT  CK_sSex 
5.15ʹCREATE DEFAULT䴴Ĭ϶
	CREATE DEFAULT DEF_sex
	AS  С
5.16һдĬ϶ѧԱϡ
	exec sp_bindefault 'def_sex', 'student.sSex'
	go
5.17󶨵Ĭ϶ʵִ£
	exec sp_unbindefault  'student.sSex'
5.18ɾdef_sex 
	DROP  DEFAULT  def_sex
5.19һ򣬸ùֻȡ0-100ֵ֮
	create rule  ch_chengji 
	as 
	@range >= 0 and @range < = 100
5.20´ch_chengjiѧϰɼĳɼ
	exec sp_bindrule 'ch_chengji', 'grade.gradenum'
5.21󶨵Ĺ
	exec sp_unbindrule  'grade.gradenum'
5.22ɾch_chengji 
	DROP  RULE  ch_chengji
