DDL on Table

education ddl sql server

after creating a database , to store data in the database would have to make

table that serves as a container for the data , in making a table of course we must

using DDL commands as commands to create , modify , and delete objects

The following is the syntax structure DDL used to create a table :

CREATE TABLE [ Table Name ]

(

)

to determine the field that we will create , in parentheses we isikian field names and

data type . example :

CREATE TABLE [ Table Name ]

(

 field1 char ( 5 ) ,

 field2 varchar ( 10 ) ,

 field3 int

)

in making a table we must define a unique field , to mark the primary key . example :

CREATE TABLE [ Table Name ]

(

 field1 char ( 5 ) primary key ,

 field2 varchar ( 10 ) ,

 field3 int

)

sample making tables to keep user data

CREATE TABLE t_user

(

 userID varchar ( 10 ) primary key ,

 name varchar ( 20 ) ,

)

The following is the syntax structure DDL used to alter a table :

ALTER TABLE [ Table Name ] statement

example in the use of alter table :

ALTER TABLE ADD COLUMNS t_user int age

DDL syntax to remove the last table :

DROP TABLE [ Table Name ]

example of use :

DROP TABLE t_user