The four main categories of SQL statements are as follows:
- Malvar DML (Data Manipulation Language)
2. buy modafinil online from india DDL (Data Definition Language)
3. stichometrically DCL (Data Control Language)
4. TCL (Transaction Control Language)
DML (Data Manipulation Language)
DML statements affect records in a table. These are basic operations we perform on data such as selecting a few records from a table, inserting new records, deleting unnecessary records, and updating/modifying existing records.
DML statements include the following:
SELECT – select records from a table
INSERT – insert new records
UPDATE – update/Modify existing records
DELETE – delete existing records
DDL (Data Definition Language)
DDL statements are used to alter/modify a database or table structure and schema. These statements handle the design and storage of database objects.
CREATE – create a new Table, database, schema
ALTER – alter existing table, column description
DROP – delete existing objects from database
DCL (Data Control Language)
DCL statements control the level of access that users have on database objects.
GRANT – allows users to read/write on certain database objects
REVOKE – keeps users from read/write permission on database objects
TCL (Transaction Control Language)
TCL statements allow you to control and manage transactions to maintain the integrity of data within SQL statements.
BEGIN Transaction – opens a transaction
COMMIT Transaction – commits a transaction
ROLLBACK Transaction – ROLLBACK a transaction in case of any error