SQL Structured Query Language

One: Data query Language (dql:data query Language):

Its statement, also known as a "data retrieval statement," is used to obtain data from a table to determine how the data is given in the application. Reserved word select is the most used verb for dql (and all SQL), and the other dql commonly used reserved words are where,order by,group by and having. These dql reserved words are often used in conjunction with other types of SQL statements.

Two: Data manipulation language (Dml:data manipulation Language):

Its statements include verb INSERT, update, and DELETE. They are used to add, modify, and delete rows in a table, respectively. Also known as the action query language.

Three: Transaction processing language (TPL):

Its statement ensures that all rows of the table affected by the DML statement are updated in a timely manner. The TPL statement includes begin TRANSACTION,COMMIT and rollback.

Four: Data Control Language (DCL):

Its statements are licensed through grant or revoke to determine access to database objects for individual users and groups of users. Some RDBMS can use grant or revoke to control access to individual columns of a table.

Five: Data definition language (DDL):

Its statements include verb create and drop. Create a new table or delete a table (creat table or drop tables) in the database, add an index to the table, and so on. The DDL includes many reserved words related to the data obtained in the Human database directory. It is also part of the action query.

Six: Pointer control Language (CCL):

Its statements, like declare cursor,fetch into and update WHERE current, are used to operate on separate rows for one or more tables.

SQL Structured Query Language