Identifying Datatype Of A Column In An Sqlite Android Cursor

Is there any way to identify the datatype of a column in a cursor in Android. The cursor object has a number of methods to get the columnname, column value. I want to find out the

Solution 1:

Per the SQLite documentation (http://www.sqlite.org/datatype3.html) columns in SQLite don't have a datatype -- the values in those columns do.

Any column in an SQLite version 3 database, except an INTEGER PRIMARY KEY column, may be used to store a value of any storage class.

If you're using API level 11 or above then the cursor supports getType() (see http://developer.android.com/reference/android/database/AbstractWindowedCursor.html#getType(int)).

If you're using an earlier API level, and you know that all the results in a given cursor come from the same table then you could do something like (untested):

// Assumes "cursor" is a variable that contains the cursor you're// interested in.StringtableName="..."; // The name of the tableSQLiteDatabasedb= cursor.getDatabase();
String[] names = cursor.getColumnNames();

for (name : names) {
    CursortypeCursor= 
        db.rawQuery("select typeof (" + name + ") from " + tableName;
    typeCursor.moveToFirst();
    Log.v("test", "Type of " + name + " is " + typeCursor.getString(0);
}

But that will (I expect) fail if the passed in cursor was (for instance) the result of a db.rawQuery() call that joined two or more tables.

Solution 2:

The answer or NiK, is fine. But if your db is empty, his code crashes. I suggest use:

StringQuery="PRAGMA table_info(my_table_name)"; 
Cursormy_cursor= db.rawQuery(Query, null); 
my_cursor.moveToFirst();
Column_name = my_cursor.getString(my_cursor.getColumnIndex("name"));
Column_type = my_cursor.getString(my_cursor.getColumnIndex("type"));

Solution 3:

I didn't tested yet but, try to use cursor.getType(i)

Like this:

publicstatic List resultSetToArrayListAndroid(Cursor cursor)throws SQLException {
    intcolumns= cursor.getColumnCount();
    ArrayListlist=newArrayList();
    while (cursor.moveToNext()) {
        HashMaprow=newHashMap(columns);
        for (inti=1; i <= columns; ++i) {
            switch (cursor.getType(i))  {
                case Cursor.FIELD_TYPE_FLOAT:
                    row.put(cursor.getColumnName(i), cursor.getFloat(i));
                    break;
                case Cursor.FIELD_TYPE_INTEGER:
                    row.put(cursor.getColumnName(i), cursor.getInt(i));
                    break;
                case Cursor.FIELD_TYPE_STRING:
                    row.put(cursor.getColumnName(i), cursor.getString(i));
                    break;
            }
        }
        list.add(row);
    }
    return list;
}

Solution 4:

You should use meta data from sqlite Database :

http://developer.android.com/reference/java/sql/ResultSetMetaData.html

You get this item by using getMetaData() on a ResultSet().

So, it's not the usual way of using a sqlite database in android that you shall use, but the usual JDBC way :

1. get a connection (through driver manager getConnection)
2. get a statement (through connection.createStatement)
3. get a resultset (through statement.executeQuery)
4. get the meta data (through resultset.getMetaData)

Regards, Stéphane