Deleting row in Sqlite table - android

I know it's been asked a million times but I still cannot get it to work. I'm trying to delete a row from my sqlite database but I keep getting an error. I'm sure it's to do with my syntax but I cannot get the correct syntax.
heres my delete method
public void deleteRouteNote(int notePosition){
SQLiteDatabase db = getWritableDatabase();
db.delete(TABLE_ROUTE_NOTE, COLUMN_NOTE + COLUMN_ROUTE_NOTE_POSITION + "where" + COLUMN_ROUTE_NOTE_POSITION + "=" + notePosition, null);
db.close();
and the error I'm getting
android.database.sqlite.SQLiteException: no such column: routeNotewhererouteNotePosition (code 1): , while compiling: DELETE FROM route_note WHERE routeNotewhererouteNotePosition=9
thanks for any help!!
EDIT:
Heres how I insert the data
/////Add route note row to table
public void addRouteNote(RouteNote routeNote){
ContentValues values = new ContentValues();
values.put(COLUMN_NOTE, routeNote.get_routeNote());
values.put(COLUMN_ROUTE_NOTE_POSITION, routeNote.get_routeNotePosition());
SQLiteDatabase db = getWritableDatabase();
db.insertWithOnConflict(TABLE_ROUTE_NOTE , null, values, SQLiteDatabase.CONFLICT_REPLACE);
db.close();
}

Try this
db.delete(TABLE_ROUTE_NOTE, COLUMN_ROUTE_NOTE_POSITION + " = " + notePosition, null)

From the docs,
table String: the table to delete from
whereClause String: the optional WHERE clause to apply when deleting. Passing null will delete all rows.
whereArgs String: You may include ?s in the where clause, which will be replaced by the values from whereArgs. The values will be
bound as Strings.
So according to this your delete clause might be something like this,
db.delete(TABLE_ROUTE_NOTE,COLUMN_ROUTE_NOTE_POSITION + "=? ,new String[]{notePosition});

Related

How to delete the rows from a table where a column contains a specific String?

As my title question, I want to delete some rows of table on SQLite where contains specific string.
Here are my methods I tried but there are no any row is deleted. I checked table of SQLite database by get it out and put in to DB Browser for SQLite which is downloaded from https://sqlitebrowser.org/
public void delete1(String table,String COLUMN,String link) {
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE FROM "+table+" WHERE "+COLUMN+" LIKE "+link+"%");
}
public void delete2(String table,String name){
SQLiteDatabase db = this.getWritableDatabase();
db.delete(table, "PRODUCTNAME" + "LIKE ?", new String[]{name+"%"}) ;
}
Could you tell me how to do it or how have i to correct code ?
using db.delete(table, "PRODUCTNAME " + "LIKE ?", new String[]{name+"%"}) ; will only delete rows that start with the value in name.
Perhpas you want :-
db.delete(table, "PRODUCTNAME " + "LIKE ?", new String[]{"%"+name+"%"}) ;
Then it would delete rows that contain the value rather than start with the value.
With db.execSQL("DELETE FROM "+table+" WHERE "+COLUMN+" LIKE "+link+"%"); you need to enclose the string in single quotes and assuming that you want to delete a row that contains the value then use :-
db.execSQL("DELETE FROM "+table+" WHERE "+COLUMN+" LIKE '%"+link+"%'");
Using the delete convenience method (the first part) is the better option as it protects against SQL Injection, it properly encloses the value, builds the underlying SQL and also returns the number of affected (deleted) rows.
If you use the following, this will write dome debugging information that may assist in debugging :-
public void delete2(String table,String name){
SQLiteDatabase db = this.getWritableDatabase();
Log.d("DELETEINFO","Attempting to delete rows with \n\t->" + name);
int deletedCount = db.delete(table, "PRODUCTNAME " + "LIKE ?", new String[]{"%"+name+"%"}) >0) ;
Log.d("DELETEINFO","Deleted " + deletedCount + " rows.");
}

Replace function in SQLITE

I was trying to duplicate this SQLite statement from the line of code below:
Cursor cursor = db.rawQuery("update tbl_details SET ticket = replace(ticket, " + tempID + ", " + ticket + ")", null);
to this one:
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put("ticket", "replace(ticket, " + tempID + ", " + ticket + ")");
db.update("tbl_details", cv, null, null);
return true;
What I am trying to do is to get a New ID and replace all instances of the old temporary ID in the database. But the code above is changing all the records in ticket column.
Please help. Thank you!
You can use ContentValues to bind literal values only, not expressions like replace(...).
To run the raw UPDATE SQL, just use execSQL() instead of rawQuery(). rawQuery() alone won't actually run the code until the returned Cursor is moved.

Delete specific record in sqlite table based on two criteria: _id and column

I have created a sqlite table for my android app, this table has 5 columns and multiple rows, the columns being: _id, column1, column2, column3, column4.
I want to delete a specific record, for instance the record stored in column3 corresponding to _id (in a different class are the getters and setters, for this I've named the class "TableHandler")
I guess that I'm a bit confused, following is what I was planning, but for column3 I'm not sure what should be the argument, I just want to delete whatever is in that column position corresponding to _id
public void deleteValueColumn3(TableHandler value){
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_NAME, KEY_ID + " = ? AND " + KEY_COLUMN3 + " = ?",
new String[] {String.valueOf(value.getID()), ?????????);
db.close();
}
The ???????? is that I'm stuck there, maybe the whole method needs to be rewritten, I would appreciate your input.
Thanks
If you want to delete the whole record, just use the _id of the record in delete method, because that is the primary key for your table and therefore is unique. If you'd rather keep the record, you con always use the SQLiteDatabase.update method, specifying null as the new value that will replace column3 value; check out that column3 declaration has no NOT NULL tag, otherwise that could easily throw exception at you.
SQLite does not allow you to delete columns for a specific row.
You can only delete ROWS of data (delete the row that has the column _ID = 1).
Here's a quick tutorial on SQL.
How about updating that column with a null value, rather than using delete()?
ContentValues cv = new ContentValues();
cv.putNull(KEY_COLUMN3);
db.getWritableDatabase().update(
TABLE_NAME,
cv,
KEY_ID + "=?",
new String[]{String.valueOf(keyIdValue)});

Android unable to escaping single quote character while SQLite database update

Hi in my database i have a string like "computer's" , i am fetching it from database and displaying listview, when i click on the list item it should store to one of my database table. I am doing it as below but it is getting crashed
public void updateFav(String key, int value) {
SQLiteDatabase db = mDbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
C_FAV=C_FAV.replaceAll("'","''");
values.put(C_FAV, value);
db.update(tableName, values, C_KEY + "='" + key.trim() + "'", null);
db.close();
}
Below is my trace
12-12 17:55:49.291: E/AndroidRuntime(18184): android.database.sqlite.SQLiteException: near "s":
syntax error (code 1): , while compiling: UPDATE fav SET favorite=? WHERE key='computer's'
You're escaping the apostrophes in C_FAV which seems to be a column name but not in key.
Consider using ? placeholder and bind arguments instead, e.g.
db.update(tableName, values, C_KEY + "=?", new String[] { key.trim() });

Inserting data to SQLite table with constraint failure

Inserting data to SQLite table with constraint failure
I'm trying to insert data into SQLite table on Android. _id is primary key of the table and I am inserting a row using this method:
public void addSomeData(int id, String datetime) {
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_ID, id);
contentValues.put(KEY_DATETIME, datetime);
mDb.insert(TABLE, null, contentValues);
}
The problem I get is that sometimes primary key constraint is validated and I would like to use something like INSERT IF NOT EXISTS, but preferably something that would work with ContentValues. What are my options? I understand that insertOrThrow() and insertWithOnConflict() methods only return different values, or should I use one of these methods?
Use insertWithOnConflict() with CONFLICT_IGNORE.
Will return ROWID/primary key of new or existing row, -1 on any error.
In my case "constraint failure" happened because of I had some tables which are depended on each other. As for the "insert if not exist", you can query with this id and you check if the cursor's count is bigger than zero. Check the method I'm already using in my app.
public boolean isRowExists(long rowId) {
Cursor cursor = database.query(this.tableName, this.columns, DBSQLiteHelper.COLUMN_ID + " = ? ", new String[] { "" + rowId }, null, null, null);
int numOfRows = cursor.getCount();
cursor.close();
return (numOfRows > 0) ? true : false;
}
to do so you could simply query the db to see if a row with that key exists and insert the new row only if the query returns no data.

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