JAVA如何使用SQL语句??
如何调用呢?
[解决办法]
jdbc连接 不就行吗?
[解决办法]
举个例子
import java.sql.*;
public class JDBCSample {
public static void main(java.lang.String[] args) {
try {
// 这里加载驱动
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}
catch (ClassNotFoundException e) {
System.out.println("Unable to load Driver Class");
return;
}
try {
// 所有的驱动都必需使用try/catch块来接收异常
// 必需指定 数据库URL, 用户名, 密码
Connection con = DriverManager.getConnection("jdbc:odbc:companydb","", "");
// 创建一个可执行的SQL描述
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT FIRST_NAME FROM EMPLOYEES");
// 显示SQL结果
while(rs.next()) {
System.out.println(rs.getString("FIRST_NAME"));
}
// 释放数据库资源
rs.close();
stmt.close();
con.close();
}
catch (SQLException se) {
// 输出数据库连接错误信息
System.out.println("SQL Exception: " + se.getMessage());
se.printStackTrace(System.out);
}
}
}
[解决办法]
同上但是要注意的是
Class.forName("");//括号里的字符窜是数据库驱动 不同数据库驱动不同 根据你的实际情况加载
DriverManager.getConnection("","","");//三个字符窜和你的数据库对应的 不同数据库也不同
[解决办法]
那确实，无非就是三步曲！
[解决办法]
建议去google一下,效果比在论坛问好
[解决办法]
package one;
import java.sql.*;
import com.microsoft.jdbc.sqlserver.SQLServerDriver;
public class lianjie {
public lianjie() {
}
public Connection con()
{
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
Connection cong=DriverManager.getConnection("jdbc:microsoft:sqlserver://127.0.0.1:1433;databaseName=book","sa","sa");
System.out.println("连接成功");
return cong;
} catch (Exception ex) {
System.out.println("连接失败"+ex.toString());
return null;
}
}
}
以上是连接数据库SQLServer2000的代码
[解决办法]
import java.sql.*;
public class com {
public Connection lianjie()//连接数据库的方法
{
try
{
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
Connection conn= DriverManager.getConnection("jdbc:sqlserver://127.0.0.1:1433;databaseName=book","sa","sa");
System.out.println(" 连接成功");
return conn;
}catch(Exception ex)
{
System.out.print("连接的方法有问题"+ex.getMessage());
return null;
}
}
public static void main(String[] args) {
com c=new com();
c.lianjie();
}
}
//以上是SQL2005连接数据库的方法,是成功的
[解决办法]
import java.sql.*;
public class TestData {
Connection conn = null;
Statement st = null;
ResultSet rs = null;
//查询数据
public void SelectData() {
try {
conn = new Database().getConn();
st = conn.createStatement();
String sql = "select * from user";
rs = st.executeQuery(sql);
while (rs.next()) {
System.out.print(rs.getString("userid") + "-");
System.out.print(rs.getString("username") + "-");
System.out.print(rs.getString("password") + "-");
System.out.println(rs.getString("email"));
}
this.Close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//插入数据
public void InsertData() {
try {
conn = new Database().getConn();
st = conn.createStatement();
String sql = "insert into user values('3','aaa','lyb','lyb@163.com')";
int rows = st.executeUpdate(sql);
this.Close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//带参数插入数据
public void PreInsertData() {
try {
conn = new Database().getConn();
String sql = "insert into user(userid,username,password,email) values(?,?,?,?)";
//String sql="select * from user where username=?";
PreparedStatement ps = conn.prepareStatement(sql,ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
ps.setString(1, "4");
ps.setString(2, "mmm");
ps.setString(3, "mmm");
ps.setString(4, "mmm@163.com");
rs=ps.executeQuery();
//this.Close();
/*while(rs.next()){
System.out.print(rs.getString("username"));
}*/
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//修改数据
public void UpdateData() {
try {
conn = new Database().getConn();
st = conn.createStatement();
String sql = "update user set username='lyb11' where username='lyb'";
int rows = st.executeUpdate(sql);
// this.Close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//删除数据
public void DelData() {
try {
conn = new Database().getConn();
st = conn.createStatement();
String sql = "delete from user where username='asd'";
int rows = st.executeUpdate(sql);
// this.Close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void Close() {
try {
rs.close();
st.close();
conn.close();
} catch (SQLException e) {
System.out.print("关闭数据库出错~~");
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
[解决办法]
package com.zyh.connectiondb;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class ConnectMysqlDB {
public static void main(String[] args) {
String driverName ="com.mysql.jdbc.Driver";
String url ="jdbc:mysql://localhost:3306/person?user=root&password=root";
String sql ="select * from t_zyh_test";
try {
Class.forName(driverName);
Connection conn = DriverManager.getConnection(url);
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(sql);
while (rs.next()) {
String name =rs.getString(2);
System.out.println("name==>"+name);
}
} catch (Exception e){
e.printStackTrace();
}
}
}
网上大把的例子，兄弟多看书。谢谢
