20170302
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity {
private TextView textView;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SQLiteDatabase db = SQLiteDatabase.create(null);
db.execSQL("create table Test(id integer primary key, name text, age integer)");
db.execSQL("insert into test values('1', 'Bob', '20')");
db.execSQL("insert into test values('2', 'Tom', '30')");
db.execSQL("insert into test values('3', 'Joe', '40')");
db.execSQL("insert into test values('4', 'Dan', '50')");
db.execSQL("insert into test values('5', 'Jim', '60')");
Cursor c = db.rawQuery("select * from Test", null);
String info ="";
while (c.moveToNext()) {
for (int i = 0;i < c.getColumnCount();i++) {
info += c.getString(i);
}
info += "\n";
}
db.close();
textView = new TextView(this);
setContentView(textView);
textView.setText(info);
}
}
20170302
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private final static String DB_NAME = "test.db";
private final static String DB_TABLE = "test";
private final static int DB_VERSION = 1;
private SQLiteDatabase db;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DBHelper dbHelper = new DBHelper(this);
db = dbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("id", "0");
values.put("info", "AAAAAAAAAAAAAA");
db.update(DB_TABLE, values, null, null);
db.insert(DB_TABLE, "", values);
Cursor c = db.query(DB_TABLE, new String[]{"id", "info"},"id='0'", null, null, null, null);
c.moveToFirst();
Toast.makeText(getApplicationContext(),c.getString(1),Toast.LENGTH_SHORT).show();
c.close();
}
private static class DBHelper extends SQLiteOpenHelper {
public DBHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table if not exists "+
DB_TABLE+"(id text primary key,info text)");
}
public void onUpgrade(SQLiteDatabase db,
int oldVersion, int newVersion) {
db.execSQL("drop talbe if exists "+DB_TABLE);
onCreate(db);
}
}
}