Oracle学习(十二):存储过程/存储函数

时间:2023-03-09 08:41:45
Oracle学习(十二):存储过程/存储函数

1.知识点

--第一个存储过程
/*
打印Hello World
create [or replace] PROCEDURE 过程名(參数列表)
AS
PLSQL子程序体;
调用存储过程:
1. exec sayHelloWorld();
2. begin
sayHelloWorld();
sayHelloWorld();
end;
/
*/
create or replace procedure sayHelloWorld<span style="white-space:pre"> </span>--sayHelloWorld为过程名
as
--declare
--变量说明
begin
dbms_output.put_line('Hello World');
end;
/
----------------------------------------------
/*
给指定的员工涨100的工资,并打印涨前和涨后的薪水 create [or replace] PROCEDURE 过程名(參数列表) --in为输入參数,out为输出參数
AS
PLSQL子程序体; SQL> begin
2 raiseSalary(7839);
3 raiseSalary(7566);
4 commit;
5 end;
6 /
涨前:7986 涨后:8086
涨前:5024.53 涨后:5124.53 PL/SQL 过程已成功完毕。
*/
create or replace procedure raiseSalary(eno in number)<span style="white-space:pre"> </span>--带输入參数的存储过程
as
--变量
psal emp.sal%type;
begin
--得到涨前薪水
select sal into psal from emp where empno=eno; --涨工资
update emp set sal=sal+100 where empno=eno;
--问题:要不要commit??答:不须要,由于整个事务还没有结束。等调用此存储过程后,再commit --打印
dbms_output.put_line('涨前:'||psal||' 涨后:'||(psal+100)); end;
/
-------------------------------------------------------------------
/*
查询某个员工的年收入 CREATE [OR REPLACE] FUNCTION 函数名(參数列表)
RETURN 函数值类型
AS
PLSQL子程序体; */
create or replace function queryEmpIncome(eno in number)
return number<span style="white-space:pre"> </span>
as
--变量
psal emp.sal%type;
pcomm emp.comm%type;
begin
select sal,comm into psal,pcomm from emp where empno=eno;
return psal*12+nvl(pcomm,0);
end;
/
---------------------------------------------------------------------
--OUT參数
/*
查询某个员工的姓名 月薪 职位 */
create or replace procedure queryEmpInfo(eno in number,
pename out varchar2,
psal out number,
pjob out varchar2)
as
begin
select ename,sal,empjob into pename,psal,pjob from emp where empno=eno; end;
/
--------------------------------------------------------------------
--查询某个部门中全部员工的全部信息 --1.创建一个包:MYPACKAGE
--2.在该包中定义一个自己定义类型:empcursor 类型为游标,一个存储过程:queryemp CREATE OR REPLACE
PACKAGE MYPACKAGE AS type empcursor is ref cursor; --empcursor是一个自己定义类型:引用cursor的类型作为empcursor的类型
procedure queryEmpList(dno in number,empList out empcursor); END MYPACKAGE;
==============================================
CREATE OR REPLACE
PACKAGE BODY MYPACKAGE AS procedure queryEmpList(dno in number,empList out empcursor) AS
BEGIN open empList for select * from emp where deptno=dno; END queryEmpList; END MYPACKAGE; ------------------------------------------------------------------

2.JAVA程序中測试存储过程/存储函数

package demo.util;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.ResultSet; import oracle.jdbc.OracleCallableStatement;
import oracle.jdbc.OracleTypes; import org.junit.Test; /*
*
* 性能:
* Statement < PreparedStatement < CallableStatement
* PreparedStatement:预编译SQL语句。运行的时候告诉參数。至少编辑一次
* CallableStatement:完毕对存储过程/存储函数的调用,没有编译过程,直接调用
*/
public class TestOracle { /*
* create or replace
procedure queryEmpInfo(eno in number,
pename out varchar2,
psal out number,
pjob out varchar2)
*/
@Test
public void testProcedure(){
//调用存储过程
//{call <procedure-name>[(<arg1>,<arg2>, ...)]}
String sql = "{call queryEmpInfo(?,?,? ,?)}";
Connection conn=null;
CallableStatement call = null;
try{
conn = JDBCUtils.getConnection();
call = conn.prepareCall(sql);
//赋值
call.setInt(1, 7839);
//对于out參数。申明
call.registerOutParameter(2, OracleTypes.VARCHAR);
call.registerOutParameter(3, OracleTypes.NUMBER);
call.registerOutParameter(4, OracleTypes.VARCHAR); //调用
call.execute(); //取出结果
String name = call.getString(2);
double sal = call.getDouble(3);
String job = call.getString(4);
System.out.println(name);
System.out.println(sal);
System.out.println(job);
}catch (Exception e) {
e.printStackTrace();
}finally{
JDBCUtils.release(conn, call, null);
}
} /*
* create or replace
function queryEmpIncome(eno in number)
return number
*/
@Test
public void testFunction(){
//存储函数样例
//{? = call <procedure-name>[(<arg1>,<arg2>, ...)]}
String sql = "{? =call queryEmpIncome(? )}";
Connection conn = null;
CallableStatement call = null;
try{
conn = JDBCUtils.getConnection();
call = conn.prepareCall(sql); call.registerOutParameter(1, OracleTypes.NUMBER);
call.setInt(2, 7839); //运行
call.execute(); //取出年收入
double income = call.getDouble(1);
System.out.println(income);
}catch (Exception e) {
e.printStackTrace();
}finally{
JDBCUtils.release(conn, call, null);
}
} /*
* 问题:
* 1. 光标是否被关?:是。结构集关掉后光标就关掉了。 * 2. 能否在MYSQL上运行?:不能
*/
@Test
public void testCursor(){
String sql = "{call MYPACKAGE.queryEmpList(?,? )}";
Connection conn = null;
CallableStatement call = null;
ResultSet rs =null;
try {
conn = JDBCUtils.getConnection();
call = conn.prepareCall(sql); call.setInt(1, 10);
call.registerOutParameter(2, OracleTypes.CURSOR); //运行
call.execute(); //取出集合
rs = ((OracleCallableStatement)call).getCursor(2);
while(rs.next()){
String name = rs.getString("ename");
String job = rs.getString("job");
System.out.println(name+"的职位是"+job);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
JDBCUtils.release(conn, call, rs);
}
}
}

3.用到的JDBC类

package demo.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement; public class JDBCUtils {
private static String driver="oracle.jdbc.OracleDriver";
private static String url="jdbc:oracle:thin:@localhost:1521:orcl";
private static String user="scott";
private static String password="tiger"; static{
try {
Class.forName(driver);
} catch (ClassNotFoundException e) {
throw new ExceptionInInitializerError(e);
}
} public static Connection getConnection(){
try {
return DriverManager.getConnection(url, user, password);
} catch (SQLException e) {
e.printStackTrace();
}
return null;
} /*
* 运行java程序
* java -Xms100M -Xmx200M HelloWorld
*/
public static void release(Connection conn,Statement stmt,ResultSet rs){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}finally{
rs=null;//垃圾回收:能否够通过代码干预垃圾回收?
}
} if(stmt!=null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}finally{
rs=null;//垃圾回收:能否够通过代码干预垃圾回收?
}
} if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}finally{
rs=null;//垃圾回收:能否够通过代码干预垃圾回收?
}
} }
}