如果你没有学过数据库相关的语法，或者不想写数据库语法，可以使用 Android 提供的操作数据库的一些 API 方法

范例

我们写一个 demo 操作 SQLite 数据库 lang.db 来演示 Android 提供的各个 API

1. 创建一个 空的 Android 项目 cn.twle.android.DoSQLite

2. 修改 activity_main.xml 添加四个按钮

   <?xml version="1.0" encoding="utf-8" ?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:layout_width="match_parent"
       android:layout_height="match_parent" 
       android:orientation="vertical" >
   
       <TextView
           android:layout_width="match_parent" 
           android:layout_height="wrap_content"
           android:text="ID (插入操作会忽略输入的 ID)"/>
   
       <EditText
           android:id="@+id/ms_id"
           android:layout_width="match_parent" 
           android:layout_height="wrap_content"/>
   
       <TextView
           android:layout_width="match_parent" 
           android:layout_height="wrap_content"
           android:text="开发语言，如(python)"/>
   
       <EditText
           android:id="@+id/ms_lang"
           android:layout_width="match_parent" 
           android:layout_height="wrap_content"/>
   
       <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
           android:layout_width="match_parent"
           android:layout_height="wrap_content" 
           android:orientation="horizontal" >
   
           <Button 
               android:text="插入"
               android:id="@+id/btn_insert"
               android:layout_weight="1"
               android:layout_width="wrap_content" 
               android:layout_height="wrap_content" />
   
           <Button 
               android:text="查询"
               android:layout_weight="1"
               android:id="@+id/btn_query" 
               android:layout_width="wrap_content" 
               android:layout_height="wrap_content" />
   
           <Button 
               android:text="修改"
               android:layout_weight="1"
               android:id="@+id/btn_update" 
               android:layout_width="wrap_content" 
               android:layout_height="wrap_content" />
   
           <Button 
               android:text="删除"
                android:layout_weight="1"
               android:id="@+id/btn_delete" 
               android:layout_width="wrap_content" 
               android:layout_height="wrap_content" />
   
       </LinearLayout>
   
       <TextView
           android:layout_width="match_parent" 
           android:layout_height="wrap_content"
           android:text="操作结果"/>
       <TextView
           android:id="@+id/ms_rs"
           android:layout_width="match_parent" 
           android:layout_height="wrap_content" />
   
       <TextView
           android:layout_width="match_parent" 
           android:layout_height="wrap_content"
           android:text="表里的数据"/>
   
       <TextView
           android:id="@+id/ms_all"
           android:layout_width="match_parent" 
           android:layout_height="wrap_content" />
   
   </LinearLayout>
   

3. 在 MainActivity.java 目录下创建一个 SQLite 帮助类 MsDBOpenHelper.java

   package cn.twle.android.dosqlite;
   
   import android.content.Context;
   import android.database.sqlite.SQLiteDatabase;
   import android.database.sqlite.SQLiteOpenHelper;
   
   public class MsDBOpenHelper extends SQLiteOpenHelper {
   
       public MsDBOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory,
               int version) {super(context, name, factory, version); }
   
       @Override
       //数据库第一次创建时被调用
       public void onCreate(SQLiteDatabase db) {
           db.execSQL("CREATE TABLE lang(id INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(64))");
   
       }
       //软件版本号发生改变时调用
       @Override
       public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
           db.execSQL("ALTER TABLE rank ADD phone INTEGER '0'");
       }
   }
   

4. 修改 MainActivity.java

   package cn.twle.android.dosqlite;
   
   import android.content.ContentValues;
   import android.content.Context;
   import android.database.Cursor;
   import android.database.sqlite.SQLiteDatabase;
   import android.os.Bundle;
   import android.support.v7.app.AppCompatActivity;
   import android.view.View;
   import android.widget.Button;
   import android.widget.EditText;
   import android.widget.TextView;
   
   public class MainActivity extends AppCompatActivity implements View.OnClickListener {
   
       private TextView ms_rs;
       private TextView ms_all;
   
       private EditText ms_id;
       private EditText ms_lang;
   
       private Context mContext;
       private Button btn_insert;
       private Button btn_query;
       private Button btn_update;
       private Button btn_delete;
       private SQLiteDatabase db;
       private MsDBOpenHelper msDBHelper;
       private StringBuilder sb;
       private int i = 1;
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);
   
           mContext = MainActivity.this;
           msDBHelper = new MsDBOpenHelper(mContext, "ms.db", null, 1);
           bindViews();
           queryAll();
       }
   
       private void bindViews() {
           btn_insert = (Button) findViewById(R.id.btn_insert);
           btn_query  = (Button) findViewById(R.id.btn_query);
           btn_update = (Button) findViewById(R.id.btn_update);
           btn_delete = (Button) findViewById(R.id.btn_delete);
   
           ms_id   = (EditText) findViewById(R.id.ms_id);
           ms_lang = (EditText) findViewById(R.id.ms_lang);
   
           ms_rs   = (TextView) findViewById(R.id.ms_rs);
           ms_all  = (TextView) findViewById(R.id.ms_all);
   
           btn_query.setOnClickListener(this);
           btn_insert.setOnClickListener(this);
           btn_update.setOnClickListener(this);
           btn_delete.setOnClickListener(this);
       }
   
       @Override
       public void onClick(View v) {
   
           db = msDBHelper.getWritableDatabase();
           switch (v.getId()) {
               case R.id.btn_insert:
   
                   ContentValues values1 = new ContentValues();
                   values1.put("name",ms_lang.getText().toString());
   
                   //参数依次是：表名，强行插入 null 值得数据列的列名，一行记录的数据
                   db.insert("lang", null, values1);
   
                   ms_rs.setText("插入成功");
   
                   break;
               case R.id.btn_query:
                   sb = new StringBuilder();
                   //参数依次是:表名，列名，where 约束条件，where中占位符提供具体的值，指定 group by 的列，进一步约束
                   //指定查询结果的排序方式
                   Cursor cursor = db.query("lang", null, "id=?", new String[]{ms_id.getText().toString()}, null, null, null);
   
                   if (cursor.moveToFirst()) {
                       do {
                           int pid = cursor.getInt(cursor.getColumnIndex("personid"));
                           String name = cursor.getString(cursor.getColumnIndex("name"));
                           sb.append("id：" + pid + "：" + name);
                       } while (cursor.moveToNext());
                   }
                   cursor.close();
   
                   ms_rs.setText(sb.toString());
                   break;
               case R.id.btn_update:
   
                   ContentValues values2 = new ContentValues();
                   values2.put("name",ms_lang.getText().toString());
                   //参数依次是表名，修改后的值，where条件，以及约束，如果不指定三四两个参数，会更改所有行
                   db.update("lang", values2, "id= ?", new String[]{ms_id.getText().toString()});
   
                   ms_rs.setText("更新成功");
                   break;
               case R.id.btn_delete:
                   //参数依次是表名，以及where条件与约束
                   db.delete("lang", "id = ?", new String[]{ms_id.getText().toString()});
   
                   ms_rs.setText("删除成功");
                   break;
           }
   
           queryAll();
       }
   
       public void queryAll() {
   
           db = msDBHelper.getWritableDatabase();
           sb = new StringBuilder();
           //参数依次是:表名，列名，where 约束条件，where中占位符提供具体的值，指定 group by 的列，进一步约束
           //指定查询结果的排序方式
           Cursor cursor = db.query("lang", null, null, null, null, null, null);
   
           if (cursor.moveToFirst()) {
               do {
                   int pid = cursor.getInt(cursor.getColumnIndex("id"));
                   String name = cursor.getString(cursor.getColumnIndex("name"));
                   sb.append("id：" + pid + "：" + name +"\n");
               } while (cursor.moveToNext());
           }
           cursor.close();
   
           ms_all.setText(sb.toString());
       }
   }