oracle sql开发基础课件第9章表约束

课时第一章Oracle第二章2224A–Z,a–z,0–9,_下划线)，$#CREATETABLE[schema.]tableCREATETABLE[schema.]table(IDNUMBER(4),BIRTHDAYDATE, WEIGHTNUMBER(5,2),insertinsertintoupdateupdatedossiersetcountry_code=defaultwhereASsubquery;SELECTemployee_id,last_name,salary＋1000newSalaryFROMemployees数据字典：由Oracle服务器创建和维护的表的集合，它包

LONGLONG

LONG [,columnnamedatatype]...);[,columnnamedatatype]...);ALTERALTERTABLEdossierADD(sexALTERALTERTABLEdossierMODIFY(sexMODIFY(sexDEFAULT–或具有DROPANYTABLERENAMERENAMEempTO (columndatatype[–表级约束除了NOTNULL之外，能够定义完整性约束的任NOTNULLCOUNTRY_CODECHAR(2)PRIMARYKEY,COUNTRY_NAMEVARCHAR2(50)NOTCREATETABLECOUNTRY(CREATETABLECOUNTRY(COUNTRY_CODECHAR(2)PRIMARYKEY,COUNTRY_NAMEVARCHAR2(50),NOTNULL(COUNTRY_NAME));CREATECREATE DATENOTPRIMARYKEYCREATEdepartments( CONSTRAINTdept_name_nnNOTNULL, FOREIGNKEYCREATE DATENOT

CONSTRAINTemp_dept_fkFOREIGNKEY(department_id)REFERENCESdepartments(department_id),CHECKSYSDATEUIDUSERUSERENV...,...,CHECK(salary>ALTERALTERTABLEtableADD[CONSTRAINTconstraint]typeDropPrimarykey|Unique(column)|ConstraintconstraintAlterAltertablecountrydropprimarykeyALTERALTERTABLEtableDISABLECONSTRAINTconstraintALTERALTERTABLEtableENABLECONSTRAINTFROMuser_tables;DESCDESC在约束类型中，C代表CHECK，P代表PRIMARYKEY，R代表FOREIGNKEYU代表UNIQUE，NOTNULL约束实际上fromuser_constraints;学生编号（sno）：字符型