Android连接Mysql数据库教程以及增删改查
16lz
2021-01-23
Android连接Mysql数据库教程以及增删改查学习笔记(Android与数据库 (二))
- 安装Mysql的驱动(Android需要mysql的驱动才能与mysql连接)
- 第二步,导入jar包
- 第三步,建议数据库与表
- 第四步,建立连接
- 第一步,新建数据库连接帮助类
- 第二步,修改activity_main.xml文件
- 第三步,修改MainActivity.java
- 第五步 添加网络权限
- 第六步,数据库删除操作
- 第一步,修改activity_main.xml文件(添加一个删除按钮)
- 第二步,修改MainActivity.java
- 第七步,插入数据
- 第一步,修改activity_main.xml文件(添加一个添加按钮和输入框)
- 第二步,修改MainActivity.java
- 第八步,更新数据
- 第一步,修改activity_main.xml文件(添加一个更新按钮和输入框)
- 第二步,修改MainActivity.java
安装Mysql的驱动(Android需要mysql的驱动才能与mysql连接)
Android Studio 版本 3.2 mysql驱动版本 5.0.7 (本人mysql 5.7.26 )这两个版本最好都是5.xx,不然会出现连接不了的错误(版本要一致)
关于版本不一致会出现的错误可见:
解决Android连接Mysql数据库出现的DexArchiveBuilderException异常
打开mysql驱动下载页这里我链接的是5.0.7,你可以选择其他的版本
如图点击jar下载:
第二步,导入jar包
将我们下载好的mysql-connector-java.jar包放入我们建好的项目中的lib文件夹中,如图:
右键这个jar包,选择添加为库:
如果出现下图这几个东西,表明导入成功了:
好了准备工作已经完成了。
第三步,建议数据库与表
这里我用的是HeidiSQL操作mysql的,安装好heidiSQL之后,新建数据库test如下:
然后新建表test_one以及字段id,name:
添加如下数据记录:
第四步,建立连接
第一步,新建数据库连接帮助类
新建一个DBOpenHelper.java
package com.example.mysqlconnectiontest;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;public class DBOpenHelper { private static String diver = "com.mysql.jdbc.Driver"; //加入utf-8是为了后面往表中输入中文,表中不会出现乱码的情况 private static String url = "jdbc:mysql://192.168.1.121:3306/test?characterEncoding=utf-8"; private static String user = "root";//用户名 private static String password = "123456";//密码 /* * 连接数据库 * */ public static Connection getConn(){ Connection conn = null; try { Class.forName(diver); conn = (Connection) DriverManager.getConnection(url,user,password);//获取连接 } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return conn; }}
第二步,修改activity_main.xml文件
<?xml version="1.0" encoding="utf-8"?>
第三步,修改MainActivity.java
package com.example.mysqlconnectiontest;import android.annotation.SuppressLint;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class MainActivity extends AppCompatActivity { private Button button; private TextView textView; private static final int TEST_USER_SELECT = 1; int i =0; @SuppressLint("HandlerLeak") private Handler handler = new Handler(){ @Override public void handleMessage(Message msg) { String user; switch (msg.what){ case TEST_USER_SELECT: Test test = (Test) msg.obj; user = test.getUser(); System.out.println("***********"); System.out.println("***********"); System.out.println("user:"+user); textView.setText(user); break; } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); button = (Button) findViewById(R.id.bt_send); textView = (TextView) findViewById(R.id.tv_response); } @Override protected void onStart() { super.onStart(); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { //执行查询操作 //通多点击buttoni自增长查询对应id的name if (i<=3){//因为数据库我就添加了三个数据条数,所以进行判断使其可以循环查询 i++; } else{ i=1; } //连接数据库进行操作需要在主线程操作 new Thread(new Runnable() { @Override public void run() { Connection conn = null; conn =(Connection) DBOpenHelper.getConn(); String sql = "select name from test_one where id='"+i+"'"; Statement st; try { st = (Statement) conn.createStatement(); ResultSet rs = st.executeQuery(sql); while (rs.next()){ //因为查出来的数据试剂盒的形式,所以我们新建一个javabean存储 Test test = new Test(); test.setUser(rs.getString(1)); Message msg = new Message(); msg.what =TEST_USER_SELECT; msg.obj = test; handler.sendMessage(msg); } st.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); } }); }}
第五步 添加网络权限
修改AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> //添加网络权限
运行结果如下:
第六步,数据库删除操作
第一步,修改activity_main.xml文件(添加一个删除按钮)
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity"><Button android:id="@+id/bt_send" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="查询数据表"/> <TextView android:id="@+id/tv_response" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textStyle="bold" /> <Button android:id="@+id/bt_delete" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="删除数据"/></LinearLayout>
第二步,修改MainActivity.java
package com.example.mysqlconnectiontest;import android.annotation.SuppressLint;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button button,button_delete; private TextView textView; private static final int TEST_USER_SELECT = 1; int i =0,d=0; @SuppressLint("HandlerLeak") private Handler handler = new Handler(){ @Override public void handleMessage(Message msg) { String user; switch (msg.what){ case TEST_USER_SELECT: Test test = (Test) msg.obj; user = test.getUser(); System.out.println("***********"); System.out.println("***********"); System.out.println("user:"+user); textView.setText(user); break; } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); button = (Button) findViewById(R.id.bt_send); textView = (TextView) findViewById(R.id.tv_response); button_delete = (Button) findViewById(R.id.bt_delete); } @Override protected void onStart() { super.onStart(); button.setOnClickListener(this); button_delete.setOnClickListener(this); } @Override public void onClick(View view) { switch (view.getId()){ case R.id.bt_send: //执行查询操作 //通多点击buttoni自增长查询对应id的name if (i<=3){ i++; } else{ i=1; } //连接数据库进行操作需要在主线程操作 new Thread(new Runnable() { @Override public void run() { Connection conn = null; conn =(Connection) DBOpenHelper.getConn(); String sql = "select name from test_one where id='"+i+"'"; Statement st; try { st = (Statement) conn.createStatement(); ResultSet rs = st.executeQuery(sql); while (rs.next()){ //因为查出来的数据是集合的形式,所以我们新建一个javabean存储 Test test = new Test(); test.setUser(rs.getString(1)); Message msg = new Message(); msg.what =TEST_USER_SELECT; msg.obj = test; handler.sendMessage(msg); } st.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; case R.id.bt_delete: //new一个线程执行删除数据库数据 d++; new Thread(new Runnable() { @Override public void run() { Connection conn = null; int u = 0; conn =(Connection) DBOpenHelper.getConn(); String sql = "delete from test_one where id='"+d+"'"; PreparedStatement pst; try { pst = (PreparedStatement) conn.prepareStatement(sql); u = pst.executeUpdate(); pst.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; default: } }}
运行效果如下:
表中数据全部被删掉(所以删除东西前最好加个弹出框,是否确定删除,来保证数据不会被乱删)
第七步,插入数据
第一步,修改activity_main.xml文件(添加一个添加按钮和输入框)
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity"><Button android:id="@+id/bt_send" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="查询数据表"/> <TextView android:id="@+id/tv_response" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textStyle="bold" /> <Button android:id="@+id/bt_delete" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="删除数据"/> <EditText android:id="@+id/ed_insert" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入要插入的数据" android:maxLines="2"/> <Button android:id="@+id/bt_insert" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="插入数据"/></LinearLayout>
第二步,修改MainActivity.java
package com.example.mysqlconnectiontest;import android.annotation.SuppressLint;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button button,button_delete,button_insert; private TextView textView; private static final int TEST_USER_SELECT = 1; int i =0,d=0; private EditText editText; @SuppressLint("HandlerLeak") private Handler handler = new Handler(){ @Override public void handleMessage(Message msg) { String user; switch (msg.what){ case TEST_USER_SELECT: Test test = (Test) msg.obj; user = test.getUser(); System.out.println("***********"); System.out.println("***********"); System.out.println("user:"+user); textView.setText(user); break; } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); button = (Button) findViewById(R.id.bt_send); textView = (TextView) findViewById(R.id.tv_response); button_delete = (Button) findViewById(R.id.bt_delete); button_insert = (Button) findViewById(R.id.bt_insert); editText = (EditText) findViewById(R.id.ed_insert); } @Override protected void onStart() { super.onStart(); button.setOnClickListener(this); button_delete.setOnClickListener(this); button_insert.setOnClickListener(this); } @Override public void onClick(View view) { switch (view.getId()){ case R.id.bt_send: //执行查询操作 //通多点击buttoni自增长查询对应id的name i++; //连接数据库进行操作需要在主线程操作 new Thread(new Runnable() { @Override public void run() { Connection conn = null; conn =(Connection) DBOpenHelper.getConn(); String sql = "select name from test_one where id='"+i+"'"; Statement st; try { st = (Statement) conn.createStatement(); ResultSet rs = st.executeQuery(sql); while (rs.next()){ //因为查出来的数据试剂盒的形式,所以我们新建一个javabean存储 Test test = new Test(); test.setUser(rs.getString(1)); Message msg = new Message(); msg.what =TEST_USER_SELECT; msg.obj = test; handler.sendMessage(msg); } st.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; case R.id.bt_delete: //new一个线程执行删除数据库数据 d++; new Thread(new Runnable() { @Override public void run() { Connection conn = null; int u = 0; conn =(Connection) DBOpenHelper.getConn(); String sql = "delete from test_one where id='"+d+"'"; PreparedStatement pst; try { pst = (PreparedStatement) conn.prepareStatement(sql); u = pst.executeUpdate(); pst.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; case R.id.bt_insert: //执行插入操作 new Thread(new Runnable() { @Override public void run() { Connection conn = null; int u = 0; conn =(Connection) DBOpenHelper.getConn(); String sql = "insert into test_one (name) values(?)"; PreparedStatement pst; try { pst = (PreparedStatement) conn.prepareStatement(sql); //将输入的edit框的值获取并插入到数据库中 pst.setString(1,editText.getText().toString()); u = pst.executeUpdate(); pst.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; default: } }}
运行结果如下:
数据库表记录:
第八步,更新数据
第一步,修改activity_main.xml文件(添加一个更新按钮和输入框)
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity"><Button android:id="@+id/bt_send" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="查询数据表"/> <TextView android:id="@+id/tv_response" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textStyle="bold" /> <Button android:id="@+id/bt_delete" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="删除数据"/> <EditText android:id="@+id/ed_insert" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入要插入的数据" android:maxLines="2"/> <Button android:id="@+id/bt_insert" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="插入数据"/> <EditText android:id="@+id/ed_update" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入更新的内容" android:maxLines="2"/><Button android:id="@+id/bt_update" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="更新数据"/></LinearLayout>
第二步,修改MainActivity.java
package com.example.mysqlconnectiontest;import android.annotation.SuppressLint;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button button,button_delete,button_insert,button_update; private TextView textView; private static final int TEST_USER_SELECT = 1; int i =0,d=0,z=0; private EditText editText,editText_update; @SuppressLint("HandlerLeak") private Handler handler = new Handler(){ @Override public void handleMessage(Message msg) { String user; switch (msg.what){ case TEST_USER_SELECT: Test test = (Test) msg.obj; user = test.getUser(); System.out.println("***********"); System.out.println("***********"); System.out.println("user:"+user); textView.setText(user); break; } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); button = (Button) findViewById(R.id.bt_send); textView = (TextView) findViewById(R.id.tv_response); button_delete = (Button) findViewById(R.id.bt_delete); button_insert = (Button) findViewById(R.id.bt_insert); button_update = (Button) findViewById(R.id.bt_update); editText_update = (EditText) findViewById(R.id.ed_update); } @Override protected void onStart() { super.onStart(); button.setOnClickListener(this); button_delete.setOnClickListener(this); button_insert.setOnClickListener(this); button_update.setOnClickListener(this); } @Override public void onClick(View view) { switch (view.getId()){ case R.id.bt_send: //执行查询操作 //通多点击buttoni自增长查询对应id的name if (i<=3){ i++; }else { i=1; } //连接数据库进行操作需要在主线程操作 new Thread(new Runnable() { @Override public void run() { Connection conn = null; conn =(Connection) DBOpenHelper.getConn(); String sql = "select name from test_one where id='"+i+"'"; Statement st; try { st = (Statement) conn.createStatement(); ResultSet rs = st.executeQuery(sql); while (rs.next()){ //因为查出来的数据试剂盒的形式,所以我们新建一个javabean存储 Test test = new Test(); test.setUser(rs.getString(1)); Message msg = new Message(); msg.what =TEST_USER_SELECT; msg.obj = test; handler.sendMessage(msg); } st.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; case R.id.bt_delete: //new一个线程执行删除数据库数据 d++; new Thread(new Runnable() { @Override public void run() { Connection conn = null; int u = 0; conn =(Connection) DBOpenHelper.getConn(); String sql = "delete from test_one where id='"+d+"'"; PreparedStatement pst; try { pst = (PreparedStatement) conn.prepareStatement(sql); u = pst.executeUpdate(); pst.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; case R.id.bt_insert: //执行插入操作 new Thread(new Runnable() { @Override public void run() { Connection conn = null; int u = 0; conn =(Connection) DBOpenHelper.getConn(); String sql = "insert into test_one (name) values(?)"; PreparedStatement pst; try { pst = (PreparedStatement) conn.prepareStatement(sql); //将输入的edit框的值获取并插入到数据库中 pst.setString(1,editText.getText().toString()); u = pst.executeUpdate(); pst.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; case R.id.bt_update: //new一个线程执行删除数据库数据 z++; new Thread(new Runnable() { @Override public void run() { Connection conn = null; int u = 0; conn =(Connection) DBOpenHelper.getConn(); String sql = "update test_one set name='"+editText_update.getText().toString()+"' where id='"+z+"'"; PreparedStatement pst; try { pst = (PreparedStatement) conn.prepareStatement(sql); u = pst.executeUpdate(); pst.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }).start(); break; default: } }}
运行结果如下:
关于Android连接mysql数据库以及增删改查就讲到这里了,欢迎讨论!
项目GitHub地址:https://github.com/Tobey-r1/RepositoryTest 。
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