工作中一直都是用swing,很少接触数据库,最近事少就帮着把公司服务器用csv存储用户资料信息,转移到mysql中去存储,才得以学习下mysql的存储过程。
首先在mysql中练习下存储过程的小例子:
mysql> delimiter //
mysql> create procedure hello()
-> begin
-> select 'It is not a HelloWorld';
-> end
-> //
Query OK, 0 rows affected (0.01 sec)
其中“delimiter //”的意思是定义结束符号为“//”,以此来替换mysql中的“;”
在mysql中查询上面的过程hello():
mysql> call hello()//
+------------------------+
| It is not a HelloWorld |
+------------------------+
| It is not a HelloWorld |
+------------------------+
1 row in set (0.00 sec)
建立一个简单的测试用表:
mysql> DROP TABLE IF EXISTS `userinfo`.`mapping`;
-> CREATE TABLE `userinfo`.`mapping` (
-> `cFieldID` smallint(5) unsigned NOT NULL,
-> `cFieldName` varchar(30) NOT NULL,
-> PRIMARY KEY (`cFieldID`)
-> ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
-> //
Query OK, 0 rows affected (0.14 sec)
向table mapping中插入一些初始化的数据:
mysql> load data infile 'd:\\userInfo\\field.txt' into table mapping
-> fields terminated by ',' lines terminated by '\r\n' //
Query OK, 5 rows affected (0.02 sec)
Records: 5 Deleted: 0 Skipped: 0 Warnings: 0
mysql> select *from mapping//
+----------+-------------+
| cFieldID | cFieldName |
+----------+-------------+
| 1 | MarketValue |
| 2 | P/L |
| 3 | EName |
| 4 | Nominal |
| 5 | Chg |
+----------+-------------+
5 rows in set (0.02 sec)
现在简历一个向mapping中插入一条记录并返回记录的总和
mysql> drop procedure if exists mappingProc;
-> create procedure mappingProc(out cnt int)
-> begin
-> declare maxid int;
-> select max(cFieldID)+1 into maxid from mapping;
-> insert into mapping(cFieldID,cFieldName) values(maxid,'hello');
-> select count(cFieldID) into cnt from mapping;
-> end
-> //
查找mappingProc():
mysql> call mappingProc(@a)//
mysql> select @a//
+------+
| @a |
+------+
| 6 |
+------+
mysql> select * from mapping//
+----------+-------------+
| cFieldID | cFieldName |
+----------+-------------+
| 1 | MarketValue |
| 2 | P/L |
| 3 | EName |
| 4 | Nominal |
| 5 | Chg |
| 6 | hello |
+----------+-------------+
下面是java代码用来调用MySQL的存储过程:
package kissJava.sql;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Types;
public class SQLUtils {
String url = "jdbc:mysql://127.0.0.1:3306/userInfo";
String userName = "root";
String password = "zhui007";
public Connection getConnection() {
Connection con=null;
try{
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
con = DriverManager.getConnection(url, this.userName, this.password);
}catch(SQLException sw){
}
return con;
}
public void testProc(){
Connection conn = getConnection();
CallableStatement stmt = null;
try{
stmt = conn.prepareCall("{call mappingProc(?)}");
stmt.registerOutParameter(1, Types.INTEGER);
stmt.execute();
int i= stmt.getInt(1);
System.out.println("count = " + i);
}catch(Exception e){
System.out.println("hahad = "+e.toString());
}finally{
try {
stmt.close();
conn.close();
}catch (Exception ex) {
System.out.println("ex : "+ ex.getMessage());
}
}
}
public static void main(String[] args) {
new SQLUtils().testProc();
}
}
在到MySQL中查询可看到插入一条新的记录