SQL中的DDL,DML,DCL语言_mssql学习_编程技术-你的首页-uuhomepage.com 感觉自己是比较笨的，学习过SQL语言，但是却分不太清楚DDL、DML、DCL语言，所以呢，今天就厚着脸皮问了老师，现在就自己目前的了解来总结一下。1、DDL（DATA DEFINITION LANGUAGE）数据描述语言 DDL语句不会产生还原数据，所以删除的数据也是无法恢复的 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 2、DML（DATA MANIPULATION LANGUAGE）数据操纵鱼语言 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 3、DCL（DATA CONTROL LANGUAGE）数据控制语言 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 感觉是要好那么一点了，至少不那么糊涂了，毕竟自己也学了那么久，不能什么都不知道三，不能只晓得就一个create、update、drop，嘿嘿！！！