[JDBC-2] JDBC CURD

package com.amuos.jdbc.curd;
 
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
 
import com.amuos.jdbc.util.JdbcUtils;
 
/**
 *
 * 2015-1-25
 *
 * @author <a href="mailto:472846889@qq.com">王娟</a>
 *
 */
public class CRUD {
 
    /**
     * @param args
     * @throws SQLException
     */
//    public static void main(String[] args) throws SQLException {
////         create();
////         read();
////         update();
////         delete();
//    }
 
    static void delete() throws SQLException {
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try {
            // 2.建立连接
            conn = JdbcUtils.getConnection();
            // conn = JdbcUtilsSing.getInstance().getConnection();
            // 3.创建语句
            st = conn.createStatement();
 
            String sql = "delete from contacts where id = 2";
 
            // 4.执行语句
            int i = st.executeUpdate(sql);
 
            System.out.println("Have deleted " + i + " row.");
        } finally {
            JdbcUtils.free(rs, st, conn);
        }
    }
 
    static void update() throws SQLException {
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try {
            // 2.建立连接
            conn = JdbcUtils.getConnection();
            // conn = JdbcUtilsSing.getInstance().getConnection();
            // 3.创建语句
            st = conn.createStatement();
 
            String sql = "update contacts set mail2 = 'test@163.com' where name = 'test' ";
 
            // 4.执行语句
            int i = st.executeUpdate(sql);
 
            System.out.println("Have updated " + i + " row.");
        } finally {
            JdbcUtils.free(rs, st, conn);
        }
    }
 
    static void create() throws SQLException {
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try {
            // 2.建立连接
            conn = JdbcUtils.getConnection();
            // conn = JdbcUtilsSing.getInstance().getConnection();
            // 3.创建语句
            st = conn.createStatement();
 
            String sql = "insert into contacts(name,main,mail1,mail2,relationship) values ('test', '1234565', 'test@test.com','','同事') ";
 
            // 4.执行语句
            int i = st.executeUpdate(sql);
 
            System.out.println("Have inserted " + i + " row into table contacts.");
        } finally {
            JdbcUtils.free(rs, st, conn);
        }
    }
 
    static void read() throws SQLException {
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try {
            // 2.建立连接
            conn = JdbcUtils.getConnection();
            // conn = JdbcUtilsSing.getInstance().getConnection();
            // 3.创建语句
            st = conn.createStatement();
 
            // 4.执行语句
            rs = st.executeQuery("select id, name, birthday, mobile  from contacts");
 
            // 5.处理结果
            while (rs.next()) {
                System.out.println(rs.getObject("id") + "\t"
                        + rs.getObject("name") + "\t"
                        + rs.getObject("birthday") + "\t"
                        + rs.getObject("mobile"));
            }
        } finally {
            JdbcUtils.free(rs, st, conn);
        }
    }
 
}