Oracle 11g pl/sql学习笔记
示例数据库
HR schema
重要命令
sqlplus /nologconn /as sysdbadesc dba_usersselect username,account_status from dba_users order by username;conn hr/hrdesc employeesdesc departments
一、PL/SQL基础
1.sql没有过程性控制
过程控制 + SQL = PL/SQL
IF ... THEN ... ELSE ... END IF; LOOP ... END LOOP; + SQL = PL/SQL
2.pl/sql优点：含有存储过程的sql，提高了性能，节省了网络传输
缺点：代码与oracle绑定了
3.PL/SQL 块结构
DECLARE
BEGIN
EXCEPTION
END;
3.1 Anonymous,匿名块，即时销毁，适合测试
[DECLARE]
BEGIN
[EXCEPTION]
END;
3.2 Procedure
PROCEDURE name
IS
BEGIN
[EXCEPTION]
END;
3.3 Function
FUNCTION name
RETURN datatype
IS
BEGIN
RETURN value;
[EXCEPTION]
END;