A Brief Explanation of SQL Statements and Classification

SQL statements are always necessary for any type for data manipulation, creation, transaction and controls of any database. SQL statement is not a small thing. But in this page, I try my best to give a basic idea about the SQL statement classification. Remember, all data are two types: Raw data and Meta data. Oracle SQL statements are classified into 4 categories: Data manipulation language(DML), Data definition language(DDL), Transaction control and Data control language(DCL).

SQL statements Explanation:

Data manipulation language (DML)

A data manipulation language (DML) is used to manipulate manipulate data in a database. Using DML, users can manipulate any day of a database by simple or complex commands. The data manipulation involves data insertion into the database table(s), retrieving existing data from the database, deleting data from existing tables of the database and modifying existing data from the existing table of the database. DML is mostly incorporated in SQL databases.

The following five keywords are used for SQL Data manipulation language (DML):

  • SELECT
  • INSERT
  • UPDATE
  • DELETE
  • MERGE

Data definition language (DDL)

Data definition language (DDL) is used to create and modify the structure of database objects in any type of database. Database objects include views, sachems, tables, indexes, etc.

The following six keywords are used for Data definition language (DDL):

  • CREATE
  • ALTER
  • DROP
  • RENAME
  • TRUNCATE
  • COMMENT


Data control language (DCL)

Data control language (DCL) statements are used to control access to data stored in a database.

The following two keywords are used for Data control language (DCL):

  • GRANT
  • REVOKE

Transaction control

Transaction control statements are used to control transactional processing in a database.

The following two keywords are used for Transaction control:

  • COMMIT
  • ROLLBACK
  • SAVEPOINT

Remember, SQL statement is very important. If you are looking any job related to SQL or Oracle or Microsoft SQL or MYSQL or any type of database job or doing for any job, there need always a basic clear idea about SQL statements. Moreover, each interview board of database related posts, always ask a basic question based on the basic of SQL statements. In this page, I just give you a basic idea of SQL statements. Moreover, I have a wish to create some interview type questions to publish later.

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