SQL语句操作SQLite数据库Demo

来源：互联网发布：ajax解析嵌套json数据编辑：程序博客网时间：2024/05/17 07:05

布局文件如下：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.sqlite.MainActivity"    android:orientation="vertical">    <EditText        android:id="@+id/et_name"        android:layout_width="match_parent"        android:layout_height="wrap_content"        />    <EditText        android:id="@+id/et_desc"        android:layout_width="match_parent"        android:layout_height="wrap_content"        />    <Button        android:id="@+id/btn_insert"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="insert"/>    <ListView        android:id="@+id/lv_info"        android:layout_width="match_parent"        android:layout_height="wrap_content"/></LinearLayout>

Activity代码如下：

public class MainActivity extends AppCompatActivity {    private SQLiteDatabase db;    private Button btn_insert;    private EditText et_name,et_desc;    private ListView listView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //  null表示使用默认的工厂        db = SQLiteDatabase.openOrCreateDatabase(this.getFilesDir().toString()+"/my.db3",null);        btn_insert = (Button) findViewById(R.id.btn_insert);        listView = (ListView) findViewById(R.id.lv_info);        et_name = (EditText) findViewById(R.id.et_name);        et_desc = (EditText) findViewById(R.id.et_desc);        btn_insert.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                String name = et_name.getText().toString();                String desc = et_desc.getText().toString();                try{                insertData(db,name,desc);                Cursor cursor = db.rawQuery("select * from news_info",null);                inflateCursor(cursor);                }catch (SQLiteException e){                    db.execSQL("create table news_info(_id integer primary key autoincrement," +                            " news_name varchar(50),news_desc varchar(255))");                    insertData(db,name,desc);                    Cursor cursor = db.rawQuery("select * from news_info",null);                    inflateCursor(cursor);                }            }        });    }    private void insertData(SQLiteDatabase db,String name,String desc){        db.execSQL("insert into news_info values(null,?,?)",                new String[]{name,desc});    }    private void inflateCursor(Cursor cursor){        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,R.layout.line,cursor,                new String[]{"news_name","news_desc"},new int[]{R.id.news_name,R.id.news_desc},                CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);        listView.setAdapter(adapter);    }    @Override    protected void onDestroy() {        super.onDestroy();        if(db != null && db.isOpen()){            db.close();        }    }}

运行效果：

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