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Database query android sqlite

I am stuck with one scenario in which I need to do complex query to get cursor. Don't know It is possible or not. Scenario is :
There are three tables in database.
Table Columns
Table-1 _id, name, number, ....
Table-2 _id, table1_id, col1, col2, ....
Table-3 _id, table2_id, col1, col2, ....
In these tables, when any record is inserted in table 2, corresponding table1 id is inserted in that record. Same for table2 id is inserted with table 3 record.
I want cursor for CursorAdapter to display list view of Table-3 data.
Cursor cursor = getContentResolver().query(TABLE_3_NAME, null, null, null, null);
Now need to add selection and selection args of Table-1 in this query.
Is it possible in Android?

You can use raw query to fetch from various tables. One example would be as below.
Cursor mCursor = db.rawQuery("SELECT * FROM Table-1, Table-3 " +
"WHERE Table1.id = <Whatever selection args you want> " +
"GROUP BY Table1.id", null);
This is just an example. You will have to change it as per your requirement.

You can write a SQL selection query (i.e. normal way) and you can execute using rawQuery() method.
For example:
Cursor cursor = db.rawQuery(selectQuery, null);

Android Sqlite no result

what do you think my problem is.
I am querying a sqlite database.
This code doesn't give any result.
String sql = " select _id from MYTABLE where _id = ? ";
Cursor cur = mDb.rawQuery(sql, new String[] {"5653"}) ;
but if I am executing the query without parameters like this:
String sql = " select _id from MYTABLE where _id = 5653 ";
Cursor cur = mDb.rawQuery(sql, null) ;
One row is returned as expected.
Many thanks.

That happens because the values are bound as strings, and that column is (i am guessing) an int. so the where clause will end up being
where _id = "5653"
From rawQuery javadoc for selectionArgs -
You may include ?s in where clause in the query, which will be replaced by the values from selectionArgs. The values will be bound as Strings.

Try this:
String sql = " select _id from MYTABLE where _id = '5653' ";

Android: How to access results from Cursor when INNER JOIN is performed?

I am using INNER JOIN on two tables,table1 and table2, from my SQLite Database.
How do I access the results(columns of both tables) from the cursor? The two tables have 2 columns with same name.
String query = SELECT * FROM table1 INNER JOIN table2 ON table1.id=table2.id WHERE name like '%c%';
Cursor c = newDB.rawQuery(query, null);

You can specify column names instead of using '*'.
String query = SELECT table1.id AS ID,table2.column2 AS c2,...... FROM table1 INNER JOIN table2 ON table1.id=table2.id WHERE name like '%c%';
and then access using column name ID,c2 etc .
while (cursor.moveToNext()) {
String c2 = cursor.getString(cursor.getColumnIndex("c2"));
int id = cursor.getInt(cursor.getColumnIndex("ID"));
..............
.............
}
Editing the broken link : Check rawQuery methid here http://www.vogella.com/tutorials/AndroidSQLite/article.html
and here http://www.codota.com/android/methods/android.database.sqlite.SQLiteDatabase/rawQuery for different examples

You can access the result as you would with any other query.
The only difference is that there is a chance to name conflicts, same column name on both tables. In order to solve those conflict you would need to use the table name as a prefix.
For example
Long id = c.getLong(c.getColumnIndex(tableName1 + "." + idColumnName));
If this approach doesn't work. You should write your query as follows:
String query = SELECT table1.id AS table1_id FROM table1 INNER JOIN table2 ON table1.id=table2.id WHERE name like '%c%';
Cursor c = newDB.rawQuery(query, null);
And another general note, it is better not to use "Select *..." it is preferred to write explicitly which column you would like to select.

Cursor c=databseobject.functionname() //where query is used
if(c.movetofirst()) {
do {
c.getString(columnindex);
} while(c.movetoNext());
}

I have used the following to do an inner join:
public Cursor innerJoin(Long tablebId) {
String query = SELECT * FROM table1 INNER JOIN table2 ON table1.id=table2.id WHERE name like '%c%';
return database.rawQuery(query, null);
}
You can Iterate your cursor as below:
Cursor cursor = innerJoin(tablebId);
String result = "";
int index_CONTENT = cursor.getColumnIndex(KEY_CONTENT);
cursor.moveToFirst();
do{
result = result + cursor.getString(index_CONTENT) + "\n";
}while(cursor.moveToNext());
Hope this works for you

If you know the column name then you can find it like below,
long id = cursor.getLong(cursor.getColumnIndex("_id"));
String title = cursor.getString(cursor.getColumnIndex("title"));
if you just want to see all the columns name of the returned cursor then you can use String[] getColumnNames() method to retrieve all the column names.
Hope this will give you some hint.

What is the correct syntax for SELECT statement and WHERE clause?

I am trying to explore android and I just started using SQLite database. I'm wondering on what is the right syntax for selecting a single row from a table, where the row I want to select is from the value entered from a user using editText. Thanks in advance.

I'm going to disagree with both of the answers above. What if the user enters this query:
Bobby Tables'; drop table yourTable;
See: http://xkcd.com/327/
I believe you should do this instead:
String query = "select * from TABLE_NAME WHERE column_name=?";
String[] selection = new String[1];
selection[0] = users_entered_value;
Cursor c = db.rawQuery(query, selection);
ETA: Actually, the more I think about it, the more I think you're going in the wrong direction. If your app depends on a database query returning exactly one unique match to an arbitrary string entered by the user, it's probably going to be broken a great deal of the time.
What you should probably do is something like this:
String query = "select * from TABLE_NAME WHERE column_name LIKE ?";
String[] selection = new String[1];
selection[0] = "%" + users_entered_value + "%";
Cursor c = db.rawQuery(query, selection);
and then iterate through the results and pick a "best" match according to your own criteria.
Also, you should create the table with case-insensitive matching for the column(s) you're going to be searching.

SQLiteDatabase db;
db.rawQuery("select * from yourTable where your_column_name = 'users_entered_value' limit 1", null);

SQLiteDatabase db;
// make connection to your database ;
Cursor c = null ;
String SQL = "select * from TABLE_NAME where column_name='VALUE'";
c = db.rawQuery(SQL);
c contains your result array of query you fired.
You can retrieve values using loop.

SQLite query from multiple tables using SQLiteDatabase [duplicate]

This question already has answers here:
How do I join two SQLite tables in my Android application?
(4 answers)
Closed 8 years ago.
I have 2 tables in my database, for example: Table1: id (PK), data1 and Table2: id (PK), id_table1 (FK), data2. How can I make a query like that:
SELECT * FROM Table1, Table2 WHERE Table1.id = Table2.id_table1
GROUP BY Table1.data1
I'm using SQLiteDatabase and its query() method.
Cursor mCursor = db.query(true, new String[] {"Table1","Table2"},
new String[] {"Table1.id","data1", "Table2.id", "id_table1", "data2"},
"Table1.id=Table2.id_table1", null, "Table1.data1", null,null,null);
But there's a problem with the second arg - it's only possible to use String, not String[] (like new String[] {"Table1","Table2}). What should I do to make a query from multiple tables in that way?

Try this:
Cursor mCursor = db.rawQuery("SELECT * FROM Table1, Table2 " +
"WHERE Table1.id = Table2.id_table1 " +
"GROUP BY Table1.data1", null);

So when you need to JOIN Tables, you have to use rawQuery instead of query.
So your statement
String SELECT_QUERY = SELECT * FROM Table1 t1 INNER JOIN Table2 t2 ON t1.id = t2.id GROUP BY t1.data1;
I recommend to you use JOIN because it more faster and safer then your approach. So then your rawQuery method can looks like this:
cursor = db.rawQuery(SELECT_QUERY, null);
Have look at
rawQuery in SQLiteDatabase
Regards