Why use prepare() at all? In my app, I am simply doing a query() on
one of the tables that I know must exist and have a row:
protected boolean isValid(File file)
{
boolean ok = false;
SQLiteDatabase _database = null;
Cursor cursor = null;
if (file.isFile())
{
try
{
_database =
SQLiteDatabase.openDatabase(file.getAbsolutePath(), null,
SQLiteDatabase.OPEN_READONLY);
cursor = _database.query("MyTable", null, null, null,
null, null, null);
if (cursor.moveToFirst())
ok = true;
}
catch (SQLiteException e)
{
// not ok
}
finally
{
if (cursor != null)
cursor.close();
if ((_database != null) && _database.isOpen())
_database.close();
}
}
return ok;
}
On Oct 6, 6:36 am, Bret Foreman <[email protected]> wrote:
> The following code (used to verify that a table exists) generates an
> SQLITE_SCHEMA exception occasionally. This means the schema has
> changed since the SQL statement was compiled.
>
> It's noted in the SQLite documents that this only happens when using
> sqlite3_prepare() and one should use sqlite3_prepare_v2() instead to
> avoid this problem. Those function names refer to the C interface, not
> Android Java. Does anyone know if Android's SQLiteDatabase.query
> method uses sqlite3_prepare_v2() underneath? It would seem not. If
> not, what is the recommended way to reliably query the list of tables
> in a database?
>
> String[] col = {"name"};
> cursor = myDatabase.query(
> /* table name */ "sqlite_master",
> /* columns */ col,
> /* select */ "type == 'table' AND name == '" +
> tableName +
> "'",
> /* selection args */ null ,
> /* no grouping */ null,
> /* no grouping filter */ null,
> /* ordering */ null
> );
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