DDL是Data definition Language 的缩写,意为数据定义语言,是SQL语言的四大功能之一。 用于定义数据库的三级结构,包括外模式、概念模式、内模式及其相互之间的映像,定义数据的完整性、安全控制等约束。 什么是DML? DML是Data Manipulation Language的缩写,意为数据操纵语言,是SQL语言的四大功能之一。 由DBMS提供,用于让用...
DDL是Data definition Language 的缩写,意为数据定义语言,是SQL语言的四大功能之一。 用于定义数据库的三级结构,包括外模式、概念模式、内模式及其相互之间的映像,定义数据的完整性、安全控制等约束。 什么是DML? DML是Data Manipulation Language的缩写,意为数据操纵语言,是SQL语言的四大功能之一。 由DBMS提供,用于让用...
Structured Query Language (SQL) Commands from the name itself it’s very obvious that we are going to discuss different SQL Commands and SQL Commands in DBMS but before that, we will be discussing what SQL is, its use, and its types. In an era when massive volumes of data are generated...
The full form of TCL isTransaction Control Language. TCL commands are basically used for managing and controlling the transactions in a database to maintain consistency. And it also helps a user manage all the changes made by the DML commands for maintaining its transactions. TCL lets the statem...
DCL (Data Control Language): GRANT: Gives users access privileges to the database. REVOKE: Removes access privileges given with the GRANT command. TCL (Transaction Control Language): COMMIT: Saves all changes made in the current transaction. ...
/rdbms/admin/dbmspool.sql rem @?/rdbms/admin/utlmontr.sql commit; connect system/manager @?/sqlplus/admin/pupbld.sql @?/rdbms/admin/catdbsyn.sql commit; spool off exit rem EOF Note that you’ll have to make the following modifications to this script: You must make sure that the ...
使用DBMS_LOB可以访问和处理LOB的特定部分或全部 存储过程/函数描述 APPEND(dest_lob IN OUT,src_lob) Appends one large object to another. COMPARE(lob_1, lob_2 [, amount[, offset_1 [, offset_2 ]]]) Compares two large objects. CONVERTOBLOB(dest_lob IN OUT,src_clob, amount, dest_offsetIN...
IN模式指的是执行函数时需要输入参数值,如下所示: postgres=# CREATE OR REPLACE PROCEDURE p_in(IN a_xm text) AS $$ BEGIN RAISE NOTICE 'a_xm=%',a_xm; END; $$ LANGUAGE PLPGSQL; CREATE PROCEDURE postgres=# CALL p_in('Tbase'); NOTICE: a_xm=Tbase CALL postgres=# postgres=# CREATE OR...