T-SQL Tutorial

T-SQL Statements - DML, DDL, DCL and TCL


DDL (Data Definition Language)

Data Definition Language (DDL) statements defines objects in a database. Use DDL statements to create, alter, or drop objects in a database.

CREATE - statement used to start create new objects like: database, table, view, index, temporary table, trigger, function or procedure.
ALTER - statement used to modify table name or table columns(add, drop, rename), view, trigger.
DROP - uses to drop objects in the database.
RENAME - uses to change the objects name in the database.
DISABLE TRIGGER - sets status trigger inactive.
ENABLE TRIGGER - sets status trigger active.
COLLATIONS - defines a collation of a database or table column.
UPDATE STATISTICS - updates query optimization statistics on a table or indexed view.

DML (Data Manipulation Language)

Data Manipulation Language (DML) affect the information stored in the database. Use DML statements to insert, update, and delete the rows in the database.

INSERT - insert records into a table.
DELETE - delete records into a table.
MERGE - insert, update, or delete records on a table from the results of a join.
BULK INSERT - imports records from a data file into a database table or view.
TRUNCATE TABLE - delete all rows from a table.





DCL (Data Control Language) - Permissions statements

Data Control Language (DCL) - permissions statements control which users and logins can access data and perform operations.

GRANT - statement used to grant privileges, roles or permissions on database objects.
REVOKE - uses to revokes permissions granted.

TCL (Transaction Control Language)

Transaction Control Language (TCL) commands are used to manage transactions in the database.

BEGIN DISTRIBUTED TRANSACTION - begin distributed transaction.
BEGIN TRANSACTION - begin transaction statement.
COMMIT TRANSACTION - commit transaction is the end point of a successful transaction.
COMMIT WORK - marks the end of a transaction.
ROLLBACK TRANSACTION - rolls back an unsuccessful transaction.
ROLLBACK WORK - rolls back a user-specified transaction.
SAVE TRANSACTION - sets a savepoint within a transaction.