What are the difference between DDL, DML and DCL commands? 
DDL is Data Definition Language statements. Some examples: 
- CREATE - to create objects in the database 
 - ALTER - alters the structure of the database 
 - DROP - delete objects from the database 
 - TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed 
 - COMMENT - add comments to the data dictionary 
 - GRANT - gives user's access privileges to database 
 - REVOKE - withdraw access privileges given with the GRANT command 
  
DML is Data Manipulation Language statements. Some examples: 
 
- SELECT - retrieve data from the a database 
 - INSERT - insert data into a table 
 - UPDATE - updates existing data within a table 
 - DELETE - deletes all records from a table, the space for the records remain 
 - CALL - call a PL/SQL or Java subprogram 
 - EXPLAIN PLAN - explain access path to data 
 - LOCK TABLE - control concurrency 
  
DCL is Data Control Language statements. Some examples: 
 
- COMMIT - save work done 
 - SAVEPOINT - identify a point in a transaction to which you can later roll back 
 - ROLLBACK - restore database to original since the last COMMIT 
 - SET TRANSACTION - Change transaction options like what rollback segment to use 
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	posted on 2005-04-16 14:26 
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