1 package com.example.administrator.myapplication.database.Activity;  2   3 import android.content.ContentValues;  4 import android.database.Cursor;  5 import android.database.sqlite.SQLiteDatabase;  6 import android.os.Bundle;  7 import android.support.v7.app.AppCompatActivity;  8 import android.view.View;  9 import android.widget.Button; 10 import android.widget.EditText; 11 import android.widget.Toast; 12  13 import com.example.administrator.myapplication.R; 14 import com.example.administrator.myapplication.database.MySQLiteOpenHelper; 15 import com.example.administrator.myapplication.util.Common; 16  17 public class SQLiteActivity extends AppCompatActivity { 18     Button insertBtn; 19     Button queryBtn; 20     Button deleteBtn; 21     Button updateBtn; 22     EditText titleET; 23     EditText deleteET; 24     EditText updateET; 25     String TitleReceiver; 26     String deleteReceiver; 27     String updateReceiver; 28  29     @Override 30     protected void onCreate(Bundle savedInstanceState) { 31         super.onCreate(savedInstanceState); 32         setContentView(R.layout.activity_sqlite); 33         titleET = (EditText) findViewById(R.id.titleText); 34         deleteET = (EditText) findViewById(R.id.deleteText); 35         updateET = (EditText) findViewById(R.id.updateText); 36         insertBtn = (Button) findViewById(R.id.insertData); 37         insertBtn.setOnClickListener(new View.OnClickListener() { 38             @Override 39             public void onClick(View v) { 40                 insertData(); 41             } 42         }); 43         queryBtn = (Button) findViewById(R.id.queryData); 44         queryBtn.setOnClickListener(new View.OnClickListener() { 45             @Override 46             public void onClick(View v) { 47                 queryData(); 48             } 49         }); 50         deleteBtn = (Button) findViewById(R.id.deleteData); 51         deleteBtn.setOnClickListener(new View.OnClickListener() { 52             @Override 53             public void onClick(View v) { 54                 deleteData(); 55             } 56         }); 57         updateBtn = (Button) findViewById(R.id.updateData); 58         updateBtn.setOnClickListener(new View.OnClickListener() { 59             @Override 60             public void onClick(View v) { 61                 updateData(); 62             } 63         }); 64     } 65  66     //插入数据 67     public void insertData(){ 68         TitleReceiver = titleET.getText().toString(); 69         //调用帮助类的构造函数，创建数据库 70         MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this); 71         //调用帮助类的onCreate方法，创建表 72         SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getWritableDatabase(); 73         //将保存的数据放入ContentValues中 74         ContentValues contentValues = new ContentValues(); 75         contentValues.put(Common.NewsTable.TBL_TITLE,TitleReceiver); 76         contentValues.put(Common.NewsTable.TBL_CONTENT,"内容"); 77         contentValues.put(Common.NewsTable.TBL_SRC,"图片"); 78         contentValues.put(Common.NewsTable.TBL_DATE,"日期"); 79         //调用insert方法，保存数据 80         sqLiteDatabase.insert(Common.NewsTable.TBL_NAME,null,contentValues); 81         //!!!数据库操作完成后，一定要关闭数据库 82         sqLiteDatabase.close(); 83         Toast.makeText(getApplication(),"保存数据成功！",Toast.LENGTH_SHORT).show(); 84     } 85     //查询数据 86     public void queryData(){ 87         MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this); 88         SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getReadableDatabase(); 89         //调用SQLiteDatabase的Query方法，返回数据库查询的结果集 90         Cursor cursor = sqLiteDatabase.query( 91                 Common.NewsTable.TBL_NAME, 92                 new String[]{Common.NewsTable.TBL_TITLE,Common.NewsTable.TBL_CONTENT,Common.NewsTable.TBL_SRC,Common.NewsTable.TBL_DATE}, 93                 null,null,null,null,null 94         ); 95         //！！查询对应数据的时候，一定要现获取列的索引值 96         while (cursor.moveToNext()){ 97             int titleIndex = cursor.getColumnIndex(Common.NewsTable.TBL_TITLE); 98             String title = cursor.getString(titleIndex); 99             Toast.makeText(getApplication(),title,Toast.LENGTH_SHORT).show();100         }101         //数据查询完毕以后，1:关系结果集 2.关闭SQLiteDataBase102         cursor.close();103         sqLiteDatabase.close();104         Toast.makeText(getApplication(),"查询完毕！",Toast.LENGTH_SHORT).show();105     }106     //删除数据107     private void deleteData() {108         deleteReceiver = deleteET.getText().toString();109         MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this);110         SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getWritableDatabase();111         sqLiteDatabase.delete(112                 Common.NewsTable.TBL_NAME,113                 // ?：占位符 " = ? "相当于 " = 标题 ", null114                 Common.NewsTable.TBL_TITLE+ " = ?",115                 new String[]{deleteReceiver}116         );117         sqLiteDatabase.close();118         Toast.makeText(getApplication(),"删除成功!",Toast.LENGTH_SHORT).show();119     }120     //修改数据121     private void updateData() {122         updateReceiver = updateET.getText().toString();123         MySQLiteOpenHelper mySQLiteOpenHelper = new MySQLiteOpenHelper(this);124         SQLiteDatabase sqLiteDatabase = mySQLiteOpenHelper.getWritableDatabase();125         ContentValues contentValues = new ContentValues();126         contentValues.put(Common.NewsTable.TBL_TITLE,"这是修改后的数据");127         sqLiteDatabase.update(128                 Common.NewsTable.TBL_NAME,129                 contentValues,130                 Common.NewsTable.TBL_TITLE + " = ?",131                 new String[]{updateReceiver}132         );133         sqLiteDatabase.close();134         Toast.makeText(getApplication(),"修改成功!",Toast.LENGTH_SHORT).show();135     }136 }

 1 package com.example.administrator.myapplication.database; 2  3 import android.content.Context; 4 import android.database.sqlite.SQLiteDatabase; 5 import android.database.sqlite.SQLiteOpenHelper; 6  7 import com.example.administrator.myapplication.util.Common; 8  9 /**10  * Created by Administrator on 2016-9-19.11  */12 13 //帮助类继承SQLiteOpenHelper，方法：构造函数，创建数据库，创建表，更新表14 public class MySQLiteOpenHelper extends SQLiteOpenHelper {15     private static final String DB_Name = "new.db"; //数据库后缀为db，常量用大写16     private static final int VERSION = 1; //数据库版本号17     //上下文，数据库名字，factory默认null,版本号18     /*public MySQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {19         super(context, DB_Name, factory, VERSION);20     }*/21     //实现了数据库的创建，factory默认null,版本号固定22     public MySQLiteOpenHelper(Context context) {23         super(context, DB_Name, null, VERSION);24     }25 26     //在onCreate方法中创建表，只执行一次27     @Override28     public void onCreate(SQLiteDatabase db) {29         String sql = Common.NewsTable.getCreateTableSQL();30         db.execSQL(sql);31     }32     //onUpgrade更新表33     @Override34     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {35         //先删除原表，再调用onCreate创建新表36         db.execSQL("drop table "+ Common.NewsTable.TBL_NAME);37         onCreate(db);38     }39 }

 1 package com.example.administrator.myapplication.util; 2  3 /** 4  * Created by Administrator on 2016-9-19. 5  */ 6 public class Common { 7     public static class NewsTable{ 8         public static final String TBL_NAME ="News"; 9         public static final String TBL_TITLE = "NewsTitle";10         public static final String TBL_CONTENT = "NewsContent";11         public static final String TBL_SRC = "http://www.mamicode.com/NewsImg";12         public static final String TBL_DATE = "NewsDate";13 14         public static String getCreateTableSQL(){15             String sql = "create table if not exists "16                         + TBL_NAME17                         + "("18                         + " _id integer primary key autoincrement,"19                         + TBL_TITLE + " text,"20                         + TBL_CONTENT + " text,"21                         + TBL_SRC + " text,"22                         + TBL_DATE + " varchar(50)"23                         + ")";24             return sql;25         }26     }27 }

 1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     xmlns:tools="http://schemas.android.com/tools" 4     android:layout_width="match_parent" 5     android:layout_height="match_parent" 6     android:orientation="vertical" 7     tools:context=".database.Activity.SQLiteActivity"> 8  9     <EditText10         android:id="@+id/titleText"11         android:layout_width="match_parent"12         android:layout_height="wrap_content"13         android:hint="请输入标题" />14 15     <LinearLayout16         android:layout_width="match_parent"17         android:layout_height="wrap_content"18         android:orientation="horizontal">19 20         <TextView21             android:layout_width="wrap_content"22             android:layout_height="wrap_content"23             android:text="请输入要删除的数据" />24 25         <EditText26             android:id="@+id/deleteText"27             android:layout_width="match_parent"28             android:layout_height="wrap_content" />29     </LinearLayout>30 31     <LinearLayout32         android:layout_width="match_parent"33         android:layout_height="wrap_content"34         android:orientation="horizontal">35 36         <TextView37             android:layout_width="wrap_content"38             android:layout_height="wrap_content"39             android:text="请输入要修改的数据" />40 41         <EditText42             android:id="@+id/updateText"43             android:layout_width="match_parent"44             android:layout_height="wrap_content" />45     </LinearLayout>46 47     <Button48         android:id="@+id/insertData"49         android:layout_width="match_parent"50         android:layout_height="wrap_content"51         android:text="添加数据" />52 53     <Button54         android:id="@+id/queryData"55         android:layout_width="match_parent"56         android:layout_height="wrap_content"57         android:text="查找数据  " />58 59     <Button60         android:id="@+id/updateData"61         android:layout_width="match_parent"62         android:layout_height="wrap_content"63         android:text="修改数据" />64 65     <Button66         android:id="@+id/deleteData"67         android:layout_width="match_parent"68         android:layout_height="wrap_content"69         android:text="删除数据" />70 </LinearLayout>