方法一
Class.forName(“com.mysql.cj.jdbc.Driver”);
需要抛出ClassNotFoundException异常
package com.javaee.code;
import java.sql.*;
/**
*TestJdbc
*/
public class jdbcTest {
public static String getMysql(){
String url = "jdbc:mysql://127.0.0.1:3306/test_db1";//定义url
// 驱动名字
String driverName = "com.mysql.cj.jdbc.Driver";
// 查询语句
String sqlString = "SELECT * FROM employee limit 1";
String result = null;
try {
// 1 加载驱动(3种方法?)
Class.forName(driverName);// 方法1
// 2 创建连接
Connection connection = DriverManager.getConnection(url,"root","123456");
// 3 通过连接获取statement
Statement statement = connection.createStatement();
// 4 statement 做一些 增删改查
ResultSet resultSet = statement.executeQuery(sqlString);
// 5 获取执行结果
while (resultSet.next()){
result = resultSet.getString(1);
}
} catch ( ClassNotFoundException | SQLException e) {
result = e.toString();
//e.printStackTrace();
}
return result;
}
public static void main(String args){
getMysql();
}
}
方法二
System.setProperty(“jdbc.drivers”, “com.mysql.cj.jdbc.Driver”);
- 出现SQLException
java.sql.SQLException: No suitable driver found for jdbc:mysql://127.0.0.1:3306/test_db1
- 原因:之前tomcat的子目录lib下的jdbc包被我删,加上,解决!
package com.javaee.code;
import java.sql.*;
/**
*TestJdbc
*/
public class jdbcTest {
public static String getMysql(){
String url = "jdbc:mysql://127.0.0.1:3306/test_db1";//定义url
// 驱动名字
String driverName = "com.mysql.cj.jdbc.Driver";
// 查询语句
String sqlString = "SELECT * FROM employee limit 1";
String result = null;
try {
System.setProperty("jdbc.drivers",driverName);// 方法2
// 2 创建连接
Connection connection = DriverManager.getConnection(url,"root","123456");
// 3 通过连接获取statement
Statement statement = connection.createStatement();
// 4 statement 做一些 增删改查
ResultSet resultSet = statement.executeQuery(sqlString);
// 5 获取执行结果
while (resultSet.next()){
result = resultSet.getString(1);
}
} catch ( SQLException e) {
result = e.toString();
//e.printStackTrace();
}
return result;
}
public static void main(String args){
getMysql();
}
}
方法三
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
package com.javaee.code;
import java.sql.*;
/**
*TestJdbc
*/
public class jdbcTest {
public static String getMysql(){
String url = "jdbc:mysql://127.0.0.1:3306/test_db1";//定义url
// 驱动名字
//String driverName = "com.mysql.cj.jdbc.Driver";
// 查询语句
String sqlString = "SELECT * FROM employee limit 1";
String result = null;
try {
// 1 加载驱动(3种方法?)
//Class.forName(driverName);// 方法1
//System.setProperty("jdbc.drivers",driverName);// 方法2
DriverManager.registerDriver(new com.mysql.jdbc.Driver());//方法3
// 2 创建连接
Connection connection = DriverManager.getConnection(url,"root","123456");
// 3 通过连接获取statement
Statement statement = connection.createStatement();
// 4 statement 做一些 增删改查
ResultSet resultSet = statement.executeQuery(sqlString);
// 5 获取执行结果
while (resultSet.next()){
result = resultSet.getString(1);
}
} catch ( SQLException e) {//|ClassNotFoundException(方法1)
result = e.toString();
//e.printStackTrace();
}
return result;
}
public static void main(String args){
getMysql();
}
}