Android - Sqlite database method undefined fot type
i've a class in this app that should create and use a database, but Eclipse tell me that the sqlite methods are undefined.
Seem to be a context problem but i don't understand how to fix, have i to extend a different class instead of Activity?
package com.android.userdata;
import android.app.Activity;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class getdata extends Activity {
private final String MY_DATABASE_NAME = "DataStore";
private final String MY_DATABASE_TABLE = "UserDat开发者_高级运维a";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.userdata);
SQLiteDatabase myDB = null;
/* Create the Database (no Errors if it already exists) */
this.createDatabase(MY_DATABASE_NAME, 1, MODE_PRIVATE, null);
myDB = this.openDatabase(MY_DATABASE_NAME, null);
myDB.execSQL("CREATE TABLE IF NOT EXISTS "
+ MY_DATABASE_TABLE
+ " (LastName VARCHAR, FirstName VARCHAR,"
+ " Country VARCHAR, Age INT(3));");
Button btn = (Button) findViewById(R.id.confirm);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getdata.this, "Hai Premuto il Pulsante", Toast.LENGTH_SHORT).show();
}
});
}
}
Thanks for your help!
I suggest you use the SQLiteOpenHelper.
It cares automatically to create a DB if it's not available...
example code:
public class DatabaseHelper extends SQLiteOpenHelper {
private static final int DB_VERSION = 1;
private static final String DB_NAME = "myDB.db";
public DatabaseHelper(Context ctx) {
super(ctx, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE myTable(_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, age INTEGER NOT NULL)";
db.execSQL(query);
db.close();
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
...
}
}
Use it like this:
...
DatabaseHelper helper = new DatabaseHelper(context);
SQLiteDatabase db = helper.getWritableDatabase();
...
I think it's easier and you don't need to care about if the DB is existing already.
Hope this helps :)
EDIT:
I have an idea... maybe it is not possible to give this string like you are doing... try to build the string before. Like this:
String query = "YOUR SQL STATEMENT";
db.execSQL(query);
db.close();
Is a possibility :)
If you need to keep your database material within an Activity extended class for whatever reason, you would define a private class like this within your getdata Activity class :
private static class DatabaseHelper extends SQLiteOpenHelper {
.. see Beasly's code example
}
精彩评论