package com.printery.conn;import java.sql.*;public class db_conn { String sDBDriver = "com.mysql.jdbc.Driver";
String sConnStr = "jdbc:mysql://localhost/printery?user=root&useUnicode=true&characterEncoding=8859_1";
Connection conn = null;
Statement stmt = null;
ResultSet rs = null; public db_conn() {
try {
Class.forName(sDBDriver);
}
catch (java.lang.ClassNotFoundException e) {
System.err.println("printery(): " + e.getMessage());
}
}///////////////////////////insert语句
public void executeInsert(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement();
stmt.executeUpdate(sql);
stmt.close();
conn.close();
}
catch (SQLException ex) {
System.err.println("printery.executeUpdate:" + ex.getMessage());
}
}///////////////////////////数据库查询
public ResultSet executeQuery(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_READ_ONLY);
rs = stmt.executeQuery(sql);
}
catch (SQLException ex) {
System.err.println("printery.executeQuery:" + ex.getMessage());
}
return rs;
}////////////////////////////update
public void executeUpdate(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement();
stmt.executeUpdate(sql);
stmt.close();
conn.close();
}
catch (SQLException ex) {
System.err.println("printery.executeQuery: " + ex.getMessage());
}
}/////////////////////////////////数据库删除
public void executeDelete(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement();
stmt.executeUpdate(sql);
stmt.close();
conn.close();
}
catch (SQLException ex) {
System.err.println("printery.executeDelete:" + ex.getMessage());
}
} public void closeStmt() {
try {
stmt.close();
}
catch (SQLException e) {
e.printStackTrace();
}
} public void closeConn() {
try {
conn.close();
}
catch (SQLException e) {
e.printStackTrace();
}
}}
String sConnStr = "jdbc:mysql://localhost/printery?user=root&useUnicode=true&characterEncoding=8859_1";
Connection conn = null;
Statement stmt = null;
ResultSet rs = null; public db_conn() {
try {
Class.forName(sDBDriver);
}
catch (java.lang.ClassNotFoundException e) {
System.err.println("printery(): " + e.getMessage());
}
}///////////////////////////insert语句
public void executeInsert(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement();
stmt.executeUpdate(sql);
stmt.close();
conn.close();
}
catch (SQLException ex) {
System.err.println("printery.executeUpdate:" + ex.getMessage());
}
}///////////////////////////数据库查询
public ResultSet executeQuery(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_READ_ONLY);
rs = stmt.executeQuery(sql);
}
catch (SQLException ex) {
System.err.println("printery.executeQuery:" + ex.getMessage());
}
return rs;
}////////////////////////////update
public void executeUpdate(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement();
stmt.executeUpdate(sql);
stmt.close();
conn.close();
}
catch (SQLException ex) {
System.err.println("printery.executeQuery: " + ex.getMessage());
}
}/////////////////////////////////数据库删除
public void executeDelete(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement();
stmt.executeUpdate(sql);
stmt.close();
conn.close();
}
catch (SQLException ex) {
System.err.println("printery.executeDelete:" + ex.getMessage());
}
} public void closeStmt() {
try {
stmt.close();
}
catch (SQLException e) {
e.printStackTrace();
}
} public void closeConn() {
try {
conn.close();
}
catch (SQLException e) {
e.printStackTrace();
}
}}
一、针对每一表建一Bean,只有setXXX和getXXX
二、用jsp输入新数值, (insert或update)
三、用Servlet接收数据,并通过语句直接判断表中的字段定义然后自动转换,并接收jsp中的数据
四、根据表单中的操作符如"Insert“等执行相应的操作。
这样,通用性很好,但现在是学会了却没有机会用啊··。(技术还未转化为money)
……
public class DL{
……
public String check(String sql){
……
while(rs.next()){
……
}
return
}
}
--------------------------
不是只简单的返回个记录集,而是通过记录集得到所需数据,然后在进行某些运算……直到返回值。
我觉得javabean好象不能这样哦。
///////////////////////////数据库查询
public ResultSet executeQuery(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_READ_ONLY);
rs = stmt.executeQuery(sql);
}
catch (SQLException ex) {
System.err.println("printery.executeQuery:" + ex.getMessage());
}
return rs;
}对数据库的操作方法进行封装。而是封装的业务逻辑,其中用到了记录集,从数据库中查询出某些值然后跟其他值通过计算,得到新的值返回