AndroidStudio使用JDBC并利用Mysql6.0进行增删改查

AndroidStudio使用JDBC并利用Mysql6.0进行增删改查

多次调用失败总结出来的 这里就不吐槽了。
String driver_url="jdbc:mysql://localhost:3306/userdb?serverTimezone=UTC&verifyServerCertificate=false&useSSL=false";

public class DBHelper {

private static Connection con;

public DBHelper() {
this.con = getConnection();
}

private static Connection getConnection(){

String driver_class="com.mysql.cj.jdbc.Driver";
String driver_url="jdbc:mysql://localhost:3306/userdb?serverTimezone=UTC&verifyServerCertificate=false&useSSL=false";
String database_user="root";
String database_password="119486119a";
try {

Class.forName(driver_class);
con=DriverManager.getConnection(driver_url,database_user,database_password);

} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return con;
}

/**
* 鎻掑叆鏁版嵁
* @param student
* @return
*/
public static int insert(User student) {
Connection conn =  getConnection();
int i = 0;
String sql = "insert into user (iduser,user_count) values(?,?)";
PreparedStatement pstmt;
try {
pstmt = (PreparedStatement) conn.prepareStatement(sql);
pstmt.setString(1, student.getId()+"");
pstmt.setString(2, student.getCout_us()+"");
//    pstmt.setString(3, student.getAge());
i = pstmt.executeUpdate();
pstmt.close();
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
return i;

}

public static int update(User student) {
Connection conn = getConnection();
int i = 0;
String sql = "update user set user_count='" + student.getCout_us() + "' where iduser='" + student.getId() + "'";
PreparedStatement pstmt;
try {
pstmt = (PreparedStatement) conn.prepareStatement(sql);
i = pstmt.executeUpdate();
System.out.println("resutl: " + i);
pstmt.close();
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
return i;
}

public static Integer getAll() {
Connection conn = getConnection();
String sql = "select * from user";
PreparedStatement pstmt;
try {
pstmt = (PreparedStatement)conn.prepareStatement(sql);
ResultSet rs = pstmt.executeQuery();
int col = rs.getMetaData().getColumnCount();
System.out.println("============================");
while (rs.next()) {
for (int i = 1; i <= col; i++) {
System.out.print(rs.getString(i) + "\t");
if ((i == 2) && (rs.getString(i).length() < 8)) {
System.out.print("\t");
}
}
System.out.println("");
}
System.out.println("============================");
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}

public static int delete(String name) {
Connection conn = getConnection();
int i = 0;
String sql = "delete from user where iduser='" + name + "'";
PreparedStatement pstmt;
try {
pstmt = (PreparedStatement) conn.prepareStatement(sql);
i = pstmt.executeUpdate();
System.out.println("resutl: " + i);
pstmt.close();
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
return i;
}

}

public class MyClass {
public static void main(String[] args) {

DBHelper.getAll();
DBHelper.insert(new User(7, 20));
DBHelper.getAll();
DBHelper.update(new User(3,10));
DBHelper.getAll();
DBHelper.delete(2+"");
DBHelper.getAll();

//        UserWindow userWindow = new UserWindow();
//        userWindow.showWindow();

System.out.println("测试中文输出");

}

}