joulesqrd
Joined: 16 Jun 2011
Posts: 7
Location: United States
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 Posted: Thu Jun 16, 2011 8:53 am Post subject: Databases--Discussion and Learning how the shit it works. |
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Here's the code (for derek's reference):
package com.atown.reviews;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class Database {
private static final String DATABASE_NAME = "reviewsData";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context){ //extends from original name
super(context, DATABASE_NAME, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE reviews (_id INTEGER PRIMARY KEY AUTOINCREMENT, " +
"title TEXT, value TEXT);");
ContentValues cv = new ContentValues();
/*cv.put("title", "Gravity, DeathStar I");
cv.put("value", "3.5303614E-7");
db.insert("reviews", null, cv);*/
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w("Reviews", "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS reviews");
onCreate(db);
}
}
private final Context mCtx;
public Database(Context c) {
mCtx = c;
}
public Database open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
public String getAllReviews(String table)
{
open();
String r = "";
Cursor result = mDb.rawQuery("SELECT title, value FROM " + table, null);
result.moveToFirst();
while (!result.isAfterLast())
{
r += result.getString(0);
r += "\n---------------------------\n";
r += result.getString(1);
r += "\n\n";
result.moveToNext();
}
result.close();
close();
return r;
}
public String getAllReviews() { return getAllReviews("reviews"); }
public void addReview(String table, String title, String text)
{
open();
ContentValues cv = new ContentValues();
cv.put("title", title);
cv.put("value", text);
mDb.insert(table, null, cv);
close();
}
public void addReview(String title, String text) { addReview("reviews", title, text); }
}
And here's the code inside write:
input=(EditText)findViewById(R.id.log_entry);
title=(EditText)findViewById(R.id.write_title);
Button submitButton = (Button)findViewById(R.id.submit_log);
submitButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Log.v("Title", title.getText().toString());
Log.v("EditText", input.getText().toString());
(new Database(v.getContext())).addReview(title.getText().toString(), input.getText().toString());
input.setText(null);
title.setText(null);
}
});
and read:
Database mDbHelper = new Database(this);
((TextView)findViewById(R.id.readView)).setText(mDbHelper.getAllReviews());
I'm going to try to use cursors to iterate through the database, but I don't know how far I can go with that. Might need to do this on friday. |
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