使用SQLiteHelper创建数据库并插入数据
2013-11-05 22:44 jediael 阅读(261) 评论(0) 编辑 收藏 举报参考《疯狂android讲义》8.4节P424
1、获取SQLiteDatabase实例有2种方法,一是直接new SQLiteDatabase(),另一种使用SQLiteHelper。一般建议使用后者。
使用SQLiteHelper插入数据的一般步骤:
package com.ljh.sqllitehelperdemo.helper; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteOpenHelper; public class DatabaseHelper extends SQLiteOpenHelper { final private String CREATE_TABLE_SQL = "create table dict(_id integer primary key autoincrement, word, detail)"; public DatabaseHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); } //1、创建SQLiteOpenHelper的子类,并重写onCreate及onUpgrade方法。 @Override public void onCreate(SQLiteDatabase db) { db.execSQL(CREATE_TABLE_SQL); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } }
package com.ljh.sqllitehelperdemo; import com.ljh.sqllitehelperdemo.helper.DatabaseHelper; import android.os.Bundle; import android.app.Activity; import android.database.sqlite.SQLiteDatabase; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends Activity { private EditText etWord = null; private EditText etDetail = null; private EditText etSearchWord= null; private TextView tvDetail = null; private Button btInsert = null; private Button btSearch = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); etWord = (EditText) findViewById(R.id.et_word); etDetail = (EditText) findViewById(R.id.et_detail); etSearchWord = (EditText) findViewById(R.id.et_search_content); tvDetail = (TextView) findViewById(R.id.tv_detail); btInsert = (Button) findViewById(R.id.bt_insert); btSearch = (Button) findViewById(R.id.bt_search); //2、获取SQLiteOpenHelper的实例,并由此获取SQLiteDatabase实例。 DatabaseHelper helper = new DatabaseHelper(this, this.getFilesDir()+"dict.db3",null,1); final SQLiteDatabase db = helper.getWritableDatabase(); btInsert.setOnClickListener(new OnClickListener(){ @Override public void onClick(View v) { String word = etWord.getText().toString(); String detail = etDetail.getText().toString(); insertData(db, word,detail); Toast.makeText(MainActivity.this, "插入数据成功", Toast.LENGTH_LONG).show(); } }); } private void insertData(SQLiteDatabase db, String word, String detail){ //4、执行SQL语句。 db.execSQL("insert into dict(word, detail) values(?,?)", new String[]{word,detail}); } }