设立主外建

设置主外建主键 alter table XXX add constraint PK_XXX primary key(ID)外键 alter table XXX add const

设置主外建
主键 alter table XXX add constraint PK_XXX primary key(ID);

外键 alter table XXX add constraint FK_XXX__YYY   foreign key(YYY_ID) references YYY(ID) ON DELETE  CASCADE;