SQLite写入读取

[android]代码库

package vedios1com.android.com.preferenceactivity;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.preference.PreferenceActivity;

/**
 * Created by Administrator on 2016/12/5 0005.
 */
public class sql extends SQLiteOpenHelper {


    public sql(Context context) {
        super(context, "db", null,1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

        db.execSQL("CREATE TABLE user(" +
                "name TEXT DEFAULT \"\"," +
                "sex TEXT DEFAULT \"\")");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}


package vedios1com.android.com.preferenceactivity;

import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sql sq=new sql(this);
//        写入数据
//        SQLiteDatabase sqLiteDatabase=sq.getWritableDatabase();
//        ContentValues cv=new ContentValues();
//        cv.put("name","张");
//        cv.put("sex","17");
//        sqLiteDatabase.insert("user",null,cv);
//        cv.put("name","li");
//        cv.put("sex","16");
//        sqLiteDatabase.insert("user",null,cv);
//        sqLiteDatabase.close();
//        读取数据
        SQLiteDatabase dbread=sq.getReadableDatabase();
       Cursor c=dbread.query("user",null,null,null,null,null,null);//不指定任何条件
        while (c.moveToNext()){
            String name=c.getString(c.getColumnIndex("name"));
            String age=c.getString(c.getColumnIndex("sex"));
            Toast.makeText(getApplicationContext(),name+age,Toast.LENGTH_LONG).show();
        }

    }
}