Mysql Modify columns, add columns, delete columns common directives

ALTER table: Add, modify, delete table columns, constraints, and other table definitions.

View column: Desc table name;

Modify table name: ALTER TABLE T_book Rename to BBB;

Add column: ALTER TABLE name add column name varchar (30);

Delete column: ALTER TABLE table name drop column name;

Modify Column name Mysql:alter table BBB change nnnnn hh int;

Modify the column name Sqlserver:exec sp_rename ' t_student.name ', ' nn ', ' column ';

Modify the Column name Oracle:lter table BBB Rename column nnnnn to HH int;

Modify Column properties: ALTER TABLE T_book modify name varchar, Sp_rename:sqlserver built-in stored procedure, with modified table definition.

MySQL view constraints, add constraints, delete constraints Add columns, modify columns, delete columns view table field information: DESC table name;

View all information about the table: Show create table table name;

Add PRIMARY KEY constraint: ALTER TABLE name add constraint primary key (Shape: Pk_ table name) primary key table name (primary key field);

Add FOREIGN KEY constraint: ALTER TABLE from TABLE ADD constraint foreign key (shape: Fk_ from Table _ Main Table) foreign key from table (foreign key field) references Main Table (primary key field);

Delete PRIMARY KEY constraint: ALTER TABLE name drop PRIMARY key;

Delete FOREIGN KEY constraint: ALTER TABLE name drop FOREIGN key foreign key (case sensitive);

Modify table name: ALTER TABLE T_book Rename to BBB;

Add column: ALTER TABLE name add column name varchar (30);

Delete column: ALTER TABLE table name drop column name;

Modify Column name Mysql:alter table BBB change nnnnn hh int;

Modify the column name Sqlserver:exec sp_rename ' t_student.name ', ' nn ', ' column ';

Modify the Column name Oracle:alter table BBB Rename column nnnnn to HH int;

Modify Column properties: ALTER TABLE T_book modify name varchar, Sp_rename:sqlserver built-in stored procedure, with modified table definition.

Mysql Modify columns, add columns, delete columns common directives