"Go" SQL statement Delete and add foreign key, primary key

--Delete foreign keys

Syntax: ALTER TABLE name DROP constraint foreign KEY constraint name

Such as:

ALTER TABLE STU_PKFK_SC DROP constraint fk_s

ALTER TABLE STU_PKFK_SC DROP constraint Fk_c

--Add foreign keys

Syntax: ALTER TABLE name ADD constraint foreign KEY constraint name foreign key (column name) references Reference foreign key table (column name)

Such as:

ALTER TABLE STU_PKFK_SC

Add Constraint fk_s

Foreign KEY (SNO)

References stu_pkfk_s (SNO)

Go

--Delete primary key

Syntax: ALTER TABLE name DROP constraint PRIMARY KEY constraint name

Such as:

ALTER TABLE stu_pkfk_s DROP constraint pk_s

Go

--Increase the primary key

Syntax: ALTER TABLE name ADD constraint PRIMARY KEY constraint name primary key (column name)

ALTER TABLE stu_pkfk_s ADD constraint pk_s primary key (SNO)

Go

Graphical Operation reference: https://jingyan.baidu.com/article/5225f26b05a25de6fa0908ae.html

"Go" SQL statement Delete and add foreign key, primary key