T-SQL DDL statements in SQL Server

This article shows how to use DDL(Data Definition Language) statements.
Uses DDL statements to create, alter, or drop objects in a SQL Server database.
The objects of a database are: schemas, tables, views, stored procedures, users, indexes, constraints, triggers, user-defined functions and types, roles, global variables.

CREATE

The CREATE statement is used to create new objexts in a SQL Server database.

The keyword CREATE DATABASE is the T-SQL statement that is used to create a new database.


				CREATE DATABASE test_database;

The CREATE SCHEMA statement is used to create a new schema in the current SQL Server database.


				CREATE SCHEMA test_schema;

The CREATE USER statement is used to create a new user database.


				CREATE USER user_test WITH PASSWORD = user_pass;

To create a table in a SQL Server database, use the CREATE TABLE command.


				CREATE TABLE books(id int, name varchar(100), price int);

To create a view in SQL Server database uses CREATE VIEW statement.


				CREATE VIEW view_books as SELECT * FROM books;

The command CREATE INDEX is used to create a index on table column.


				CREATE INDEX p_index ON books (price);

ALTER

The ALTER statement is used to alter a SQL Server database.
The T-SQL ALTER statement uses to change table names, add new columns to a table, delete or rename columns in a table.
ALTER is also used to modify views, storage procedures, triggers, indexes.


				ALTER DATABASE test_database;
				
ALTER TABLE books ADD book_date time;	
				
ALTER TABLE books DROP COLUMN book_date;	
				
ALTER VIEW view_books as SELECT * FROM books WHERE price > 50;	
				
ALTER INDEX p_index ON books REBUILD;
				
ALTER INDEX ALL ON books REBUILD; 
				
ALTER INDEX p_index ON books DISABLE;

DROP

The DROP statement is used to drop a SQL Server database.
The T-SQL DROP statement is used to delete objects from the database, objects such as: schemas, tables, views, storage procedures, indexes, users, roles, triggers.
ALTER is also used to modify views, storage procedures, triggers, indexes.


				DROP DATABASE test_database;
				
DROP SCHEMA test_schema;	
				
DROP USER test_user;
				
DROP INDEX books.p_index;	
				
DROP VIEW view_books;
				
DROP TABLE books;	
				
DROP TRIGGER test_trigger;
				
DROP PROCEDURE test_procedure;

TRUNCATE TABLE

The TRUNCATE TABLE statement is used to delete all rows from a table.


				TRUNCATE TABLE test_table;

T-SQL Tutorial

T-SQL DDL(Data Definition Language)

CREATE

ALTER

DROP

TRUNCATE TABLE