Oracle Learning 1

SQL statements are divided into 3 categories

1.ddl:data definition Language, data definition language,

The language used to define and manage all objects in the SQL database

1.CREATE creation
2.ALTER modification
3.DROP Delete
5.COMMENT comments
6.GRANT Licensing
7.REVOKE Reclaim the permissions that have been granted

Second, dml:data manipulation Language, data manipulation language,

Operations such as manipulating data in SQL are collectively referred to as data manipulation languages
1.INSERT add
2.DELETE Delete
3.UPDATE Update
4.SELECT Query
7.LOCK TABLE lock for controlling concurrency

Third, Dcl:data control Language statements. Data Controller language,

Used to grant or reclaim some kind of privilege to access the database, and to control the time and effect of database manipulation transactions , to monitor the database, etc.
Commit Commit
SavePoint Save Point
ROLLBACK rollback
Set TRANSACTION sets the characteristics of the current transaction, which has no effect on subsequent transactions.

Oracle Learning 1