Android SQLite DELETE failure

Question

I have an app which displays a ListView from SQLite database content. When I click on one of the items in the ListView, I post a message to my JNI thread and try to do a DELETE command on a table thats in the same database but its a completely different table to what has been access by the ListView.

Unfortunately the sqlite3_finalize() call fails with an error code of 1 (SQL_ERROR).

I suspect this is because the database has been opened (or is still open?) by the SimpleCursorAdapter. Would this be the case?

The DELETE statement itself works perfectly when I try it in Firefox's SQLiteManager (where I test all my SQLite statements on a copy of the database). UPDATE commands seem to work OK as do any SELECT commands - its just the DELETE that isn't working.

Do I somehow need to manually close the SimpleCursorAdapter's cursor when it has finished displaying the rows? I'm using a LoaderManager to maintain the data content.

Here's the JNI execution code:

BOOL ExecuteSQL( char *pszSQL )
{
  sqlite3_stmt *pStmt;
  int           rc;

  rc = sqlite3_prepare_v2( g_MainDB, 
                           pszSQL, 
                           -1, 
                           &pStmt, 
                           0 );
  int nFailStep = 0;

  if( rc == SQLITE_OK )
    rc = sqlite3_step( pStmt );
  else
    nFailStep = 1;

  if( rc == SQLITE_OK )
    rc = sqlite3_finalize( pStmt );
  else
    nFailStep = 2;

  if( ( rc == SQLITE_OK ) || ( rc == SQLITE_DONE ) )
    return TRUE;
  else
    nFailStep = 3;

  LogDebugf( "ExecuteSQL: rc: %d (%s) nFailStep: %d\n", rc, sqlite3_errstr( rc ), nFailStep );

  return FALSE;
}

It fails with:

ExecuteSQL: rc: 1 (SQL logic error or missing database) nFailStep: 3

Answer 1

The entire nFailStep logic is horribly wrong; the value is unlikely to be correct. Furthermore, that code does not call sqlite3_finalize if sqlite3_step is successful. Additionally, you'd get a better error message with sqlite3_errmsg :

BOOL ExecuteSQL(const char *pszSQL)
{
    sqlite3_stmt *stmt;
    int rc;

    rc = sqlite3_prepare_v2(g_MainDB, pszSQL, -1, &stmt, NULL);
    if (rc != SQLITE_OK) {
        LogDebugf("ExecuteSQL: prepare failed: %s\n", sqlite3_errmsg(g_MainDB));
        return FALSE;
    }
    rc = sqlite3_step(stmt);
    if (rc != SQLITE_ROW && rc != SQLITE_DONE) {
        LogDebugf("ExecuteSQL: step failed: %s\n", sqlite3_errmsg(g_MainDB));
        sqlite3_finalize(stmt);
        return FALSE;
    }
    sqlite3_finalize(stmt);
    return TRUE;
}