1，关系型数据路的 driver_class 和 url
1，oracle
driverClass：oracle.jdbc.OracleDriver
url：jdbc:oracle:thin:@127.0.0.1:1521:dbname
2，mysql
driverClass：com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/test?characterEncoding=utf8&useSSL=true 注意: 高版本的 mysql 需要显示指定 useSS
3，sql_server
driverClass：com.microsoft.sqlserver.jdbc.SQLServerDriver
url：jdbc:sqlserver://localhost:1433; DatabaseName=dbname
4，db2
driverClass：com.ibm.db2.jcc.DB2Driver
url：jdbc:db2://127.0.0.1:50000/dbname
5，sybase
driverClass：com.sybase.jdbc.SybDriver
url：jdbc:sybase:Tds:localhost:5007/dbname
6，postgre_sql
driverClass：org.postgresql.Driver
url：jdbc:postgresql://localhost/dbname
2，简单的增删改查，以 mysql 为例
package jdbc_util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JdbcDemo {
// 设置汉字编码 useUnicode=true&characterEncoding=UTF-8
String jdbcUrl = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8";
String className = "com.mysql.jdbc.Driver";
String user = "root";
String password = "920619";
public Connection getConnection() {
Connection connection = null;
try {
// 加载数据库驱动
Class.forName(className);
// 获取数据库连接
connection = DriverManager.getConnection(jdbcUrl, user, password);
} catch (Exception e) {
System.out.println("连接失败");
}
return connection;
}
public void closeConnection(Connection connection) {
try {
connection.close();
System.out.println("关闭成功");
} catch (SQLException e) {
System.out.println("关闭失败");
}
}
public void insert() {
String sql = "insert into user (UserName,PassWord,UserAge,UserSex) values('丙','123456', 20, 0)";
Connection connection = getConnection();
try {
//获取数据库操作类
Statement statement = connection.createStatement();
//执行 SQL 语句并返回结果
int result = statement.executeUpdate(sql);
if (result != 0) {
System.out.println("操作成功,受影响" + result + "行");
}
statement.close();
} catch (SQLException e) {
System.out.println("操作失败");
} finally {
closeConnection(connection);
}
}
public void delete() {
String sql = "delete from user where UserId in (2,3,4)";
Connection connection = getConnection();
try {
Statement statement = connection.createStatement();
int result = statement.executeUpdate(sql);
if (result != 0) {
System.out.println("操作成功,受影响" + result + "行");
}
statement.close();
} catch (SQLException e) {
System.out.println("操作失败");
} finally {
closeConnection(connection);
}
}
public void update() {
String sql = "update user set UserName = '乙' where UserId = 5";
Connection connection = getConnection();
try {
Statement statement = connection.createStatement();
int result = statement.executeUpdate(sql);
if (result != 0) {
System.out.println("操作成功,受影响" + result + "行");
}
statement.close();
} catch (SQLException e) {
System.out.println("操作失败");
} finally {
closeConnection(connection);
}
}
public void select() {
//带参数的 SQL 语句, 要设置的值用 ? 占位
String sql = "select * from user where UserId = ?";
Connection connection = getConnection();
try {
//传递 SQL 语句
PreparedStatement statement = connection.prepareStatement(sql);
//设置 SQL 语句中占位符的值
statement.setInt(1, 1);
ResultSet resultSet = statement.executeQuery();
while (resultSet.next()) {
System.out.println("UserName = " + resultSet.getString("UserName"));
System.out.println("PassWord = " + resultSet.getString("PassWord"));
System.out.println("UserAge = " + resultSet.getInt("UserAge"));
String userSex = resultSet.getInt("UserSex") == 1 ? "男" : "女";
System.out.println("UserSex = " + userSex);
}
resultSet.close();
statement.close();
} catch (SQLException e) {
System.out.println("操作失败");
} finally {
closeConnection(connection);
}
}
}