JDBC编程指南

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JDBC编程大致需如下步骤；

1.加载数据库驱动

//加载驱动Class.forName(driverClass);

2.通过DriverManager获取数据库连接

//获取数据库连接Connection conn = DriverManager.getConnection(String url,String user,String pass);

3.通过Connection对象创建Statement对象

//创建Statement对象Statement stmt=conn.createStatement();

4.使用Statement执行SQL语句

//使用Statement进行查询并返回结果集ResultSetResultSet rs=stmt.executeQuery(sql);

5.操作结果集（仅限查询类语句）

while (rs.next()) {                        for(int i=0;i<columnCount;i++) {                            System.out.println(rs.getString(i+1)+"\t");                        }                        System.out.println("\n");                    }

下面以一个Mysql数据库的例子为例，实现查询操作。

package jdbc;import com.sun.org.apache.xpath.internal.SourceTree;import java.io.FileInputStream;import java.sql.*;import java.util.Properties;/** * Created by John on 2017/8/29. */public class ExecuteSQL {    private String driver;    private String url;    private String user;    private String pass;    public void initParam(String paramFile)throws Exception {        Properties props = new Properties();        props.load(new FileInputStream(paramFile));        driver = props.getProperty("driver");        url = props.getProperty("url");        user = props.getProperty("user");        pass = props.getProperty("pass");    }    public void executeSql(String sql) throws Exception {        Class.forName(driver);        try (                Connection conn = DriverManager.getConnection(url, user, pass);                Statement stmt=conn.createStatement()        ) {            boolean hasResultSet = stmt.execute(sql);            if (hasResultSet) {                try (                        ResultSet rs = stmt.getResultSet()                ) {                    ResultSetMetaData rsmd = rs.getMetaData();                    int columnCount = rsmd.getColumnCount();                    while (rs.next()) {                        for(int i=0;i<columnCount;i++) {                            System.out.println(rs.getString(i+1)+"\t");                        }                        System.out.println("\n");                    }                }            }else{                System.out.println("该Sql语句影响的记录有"+stmt.getUpdateCount()+"条");            }        }    }    public static void main(String[] args) throws  Exception{        ExecuteSQL es = new ExecuteSQL();        es.initParam("D:\\study\\IdeaProject\\src\\jdbc\\mysql.ini");        System.out.println("----------执行查询数据的查询语句");        es.executeSql("select *"+" from people");    }}

mysql.ini文件如下：

driver=com.mysql.jdbc.Driverurl=jdbc:mysql://127.0.0.1:3306/testusr=rootpass=root

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