Eclipse下 Java对MySQL数据库操作

1. 下载Mysql驱动。

Link:http://dev.mysql.com/downloads/connector/j/

2.加载JDBC

在Eclipse中，选中相应的工程，Properties->Java Build path->add external jars->ok.

3.JDBC操作数据库的一般步骤

注册驱动 (只做一次)

Class.forName(“com.mysql.jdbc.Driver”);

建立连接(Connection)

Connection conn = DriverManager.getConnection(url, user, password);
url格式：JDBC:子协议:子名称//主机名:端口/数据库名？属性名=属性值&…
User,password可以用“属性名=属性值”方式告诉数据库；

example：

String url="jdbc:mysql://localhost:3306/test";

Connection conn;

conn = DriverManager.getConnection(url,"root","root");

创建执行SQL的语句(Statement)

执行语句

Statement是一个SQL执行器，可以用来执行一个静态的SQL语句。

Statement st = conn.createStatement();
st.executeQuery(sql);

example：

Statement stmt = conn.createStatement(); //创建Statement对象
String sql= "select * from writers";
ResultSet rs = stmt.executeQuery(sql);

执行存储过程
CallableStatement（从PreperedStatement扩展来）
cs = connection.prepareCall(“{call psname(?,?,?)}”);
cs.registerOutParameter(index, Types.INTEGER);
cs.setXXX(i, xxxx);
cs.executeUpdate();
int id=cs.getInt(index);

处理执行结果(ResultSet)

ResultSet表示一个查询结果集。
ResultSet rs = statement.executeQuery(sql);
While(rs.next()){
rs.getString(“col_name”);
rs.getInt(“col_name”);
//…
}

释放资源

释放资源的顺序是ResultSet, Statement,Connection；
Connection在使用完成后，必须关闭，ResultSet, Statement无所谓，只要Connection关闭了，它们也会被自动关闭（但资源不是立即被释放）。
Connection的使用原则是尽量晚创建，尽量早的释放。

例子：

package com.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class connect {

private Connection conn = null;
private Statement stmt = null;
private PreparedStatement preparedStatement = null;
private ResultSet rs = null;

public void readDataBase()  throws Exception{

try{
Class.forName("com.mysql.jdbc.Driver");
System.out.println("成功加载MySQL驱动！");
}catch(ClassNotFoundException e1){
System.out.println("找不到MySQL驱动!");
e1.printStackTrace();
}

String url="jdbc:mysql://localhost:3306/test";    //JDBC的URL

try {

//调用DriverManager对象的getConnection()方法，获得一个Connection对象
conn = DriverManager.getConnection(url,"root","root");
//创建一个Statement对象
stmt = conn.createStatement(); //创建Statement对象
System.out.println("成功连接到数据库！");

String sql= "select * from writers";
rs = stmt.executeQuery(sql);
writeMetaData(rs);
writeResultSet(rs);

String sql2= "insert into writers values(?,?)";
preparedStatement=conn.prepareStatement(sql2);

preparedStatement.setString(1, "11");
preparedStatement.setString(2, "TestEmail");
preparedStatement.executeUpdate();

rs = stmt.executeQuery(sql);
writeMetaData(rs);
writeResultSet(rs);

} catch (Exception e) {
throw e;
}
}

private void writeMetaData(ResultSet rs)throws SQLException{
System.out.println("The columns in the table are: ");

System.out.println("Table: " + rs.getMetaData().getTableName(1));
for  (int i = 1; i<= rs.getMetaData().getColumnCount(); i++){
System.out.print( rs.getMetaData().getColumnName(i)+"\t");
}
System.out.println();
}
public void writeResultSet(ResultSet rs) throws SQLException{

while(rs.next()){
System.out.print(rs.getString(1)+"\t");
System.out.print(rs.getString(2));
System.out.println();
}

}
private void close() {
try {
if (rs != null) {
rs.close();
}

if (stmt != null) {
stmt.close();
}

if (conn != null) {
conn.close();
}
} catch (Exception e) {

}
}
}

main：

import com.jdbc.connect;
public class Main {

public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
connect ms= new connect();
ms.readDataBase();
}

}