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| package com.example.sqlite;
import com.example.sqlite.db.DataBaseHelper;
import android.app.Activity; import android.content.ContentValues; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.TextView;
public class MainActivity extends Activity { private Button createDBButton ; private Button insertDBButton ; private Button updateDBButton ; private Button queryDBButton ; private Button deleteDBButton ; private EditText input_id ; private EditText input_name ; private TextView test ; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //此处为创建数据库, 通过按钮监听器来实现 createDBButton = (Button) findViewById(R.id.creatDB); createDBButton.setOnClickListener(new CreateDBListener()); //此处为插入数据到数据库中 insertDBButton = (Button) findViewById(R.id.insert); insertDBButton.setOnClickListener(new InsertListener()); //此处为更新数据表 updateDBButton = (Button) findViewById(R.id.update); updateDBButton.setOnClickListener(new updateListener()); //此处为更新数据表 queryDBButton = (Button) findViewById(R.id.query); queryDBButton.setOnClickListener(new queryListener()); //此处为删除数据内容 deleteDBButton = (Button) findViewById(R.id.delete); deleteDBButton.setOnClickListener(new deleteListener()); //此处为显示查询结果 test = (TextView) findViewById(R.id.result); test.setText("name") ; //此处为添加数据的选项 //input_id = (EditText) findViewById(R.id.input_id); //input_name = (EditText) findViewById(R.id.input_name); } class CreateDBListener implements OnClickListener{ @Override public void onClick(View v) { // 此处为调用另外一个类中的方法来创建数据库, 或者直接来创建数据库
String db_name = "test_mars_db_one" ; System.out.println("Create"); DataBaseHelper dbHelper = new DataBaseHelper(MainActivity.this, db_name) ; SQLiteDatabase db = dbHelper.getReadableDatabase() ; } } class InsertListener implements OnClickListener{
@Override public void onClick(View v) { //生成一个ContentValues对象 ContentValues values = new ContentValues() ; //想该对象当中插入键值对,其中键是列名,值是希望插入到这列的值,值必须 values.put("id", 1) ; values.put("name", "zhangsan") ; System.out.println("Insert"); DataBaseHelper dbHelper = new DataBaseHelper(MainActivity.this, "test_mars_db_one") ; SQLiteDatabase db = dbHelper.getWritableDatabase() ; //调用insert方法, 就可以将数据插入到数据库中 db.insert("user", null, values) ; } }
class updateListener implements OnClickListener{ @Override public void onClick(View arg0) { // 此处为更新数据内容 System.out.println("Update"); DataBaseHelper dbHelper = new DataBaseHelper(MainActivity.this, "test_mars_db_one") ; SQLiteDatabase db = dbHelper.getWritableDatabase() ; ContentValues values = new ContentValues() ; values.put("name", "zhangsanfeng") ; //第一个参数为要更新的表名 //第二个参数为一个ContentValues对象 //第三个参数是where语句 db.update("user", values, "id=?", new String[]{"1"}) ; } } class queryListener implements OnClickListener{ @Override public void onClick(View v) { // 此处为查询数据内容, 并用到cursor来实现 System.out.println("query"); DataBaseHelper dbHelper = new DataBaseHelper(MainActivity.this, "test_mars_db_one") ; SQLiteDatabase db = dbHelper.getWritableDatabase() ; Cursor cursor = db.query("user", new String[]{"id","name"}, "id=?", new String[]{"2"},null,null,null,null) ; while(cursor.moveToNext()){ String name = cursor.getString(cursor.getColumnIndex("name")) ; System.out.print("query---> " + name) ; //name += name ; test.setText(name) ; } } } class deleteListener implements OnClickListener{ public void onClick(View v) {
//此处为实现删除数据 System.out.println("delete"); DataBaseHelper dbHelper = new DataBaseHelper(MainActivity.this, "test_mars_db_one") ; SQLiteDatabase db = dbHelper.getWritableDatabase() ;
//删除特定条件的数据 //db.delete("user","id=?",new String[]{"2"}); //删除所有数据 db.delete("user",null,null);
} }
}
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