通过JDBC对MySql进行增/删/改/查操作，jdbcmysql,新建BaseDao```

通过JDBC对MySql进行增/删/改/查操作，jdbcmysql,新建BaseDao```

新建BaseDao```javaimport java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class BaseDao {
Connection con = null;
Statement st = null;
ResultSet rs = null;

/**  * 获得联接  *   * @return  */  public Connection getConnection() {      try {          // 加载驱动，这一句也可写为：Class.forName("com.mysql.jdbc.Driver");           Class.forName("com.mysql.jdbc.Driver").newInstance();        // 建立到MySQL的连接           con = DriverManager.getConnection("jdbc:mysql://localhost:3306/money_note?characterEncoding=UTF-8", "root", "root");      } catch (Exception e) {          e.printStackTrace();      }      return con;  }/**  * 关闭数据源  */  public void CloseConnection(Connection con, Statement s, ResultSet rs) {      try {          if (rs != null) {              rs.close();          }          if (s != null) {              s.close();          }          if (con != null) {              con.close();          }      } catch (SQLException e) {          e.printStackTrace();      }  }

}

测试类```javaimport java.sql.Connection;  import java.sql.ResultSet;  import java.sql.SQLException;  import java.sql.Statement;  public class Test extends BaseDao {      Connection con = null;      Statement st = null;      ResultSet rs = null;      /**      * 查询数据      */      public void find() {          con = getConnection();  // 获得联接          try {              st = con.createStatement();              rs = st.executeQuery("select * from app_user");              while (rs.next()) {                  System.out.println("编号：" + rs.getInt("uuid") + ", 姓名：" + rs.getString("userName") + ", 性别：" + rs.getString("sex") + ", 生日：" + rs.getString("birthday") + ", 住址：" + rs.getString("address"));              }          } catch (SQLException e) {              e.printStackTrace();          } finally {              CloseConnection(con, st, rs);   // 关闭联接          }      }      /**      * 添加数据      */      public void add() {          con = getConnection();          try {              st = con.createStatement();              int result = st.executeUpdate("insert into app_user(userName,passWord,sex,birthday,address) values('赵丽颖','wanying','女','1992-02-03','北京市')");              if (result > 0) {                  System.out.println("插入成功");              } else {                  System.out.println("插入失败");              }          } catch (SQLException e) {              System.out.println("插入失败");              e.printStackTrace();          } finally {              CloseConnection(con, st, rs);          }      }      /**      * 更新数据      */      public void update() {          con = getConnection();          try {              st = con.createStatement();              int result = st.executeUpdate("update app_user set address = '河南' where uuid = '3'");              if (result > 0) {                  System.out.println("更新成功");              } else {                  System.out.println("更新失败");              }          } catch (SQLException e) {              e.printStackTrace();          } finally {              CloseConnection(con, st, rs);          }      }      /**      * 删除数据      */      public void delete() {          con = getConnection();          try {              st = con.createStatement();              int result = st.executeUpdate("delete from app_user where uuid = '3'");              if (result > 0) {                  System.out.println("删除成功");              } else {                  System.out.println("删除失败");              }          } catch (SQLException e) {              e.printStackTrace();          } finally {              CloseConnection(con, st, rs);          }      }      public static void main(String[] args) {          Test test = new Test();          //test.add();          // test.update();           test.delete();          test.find();      }  }