Exception for ZIMSqlUpsertStatement with one indexed field

[chapayGhub]

Table 'Installed" has only one indexea key "app_id"
Exception when I trying to do next

        ZIMSqlUpsertStatement *sql = [[ZIMSqlUpsertStatement alloc] init];
        [sql into: [Installed table]];
        [sql column: @"app_id" value: [app_id valueForKey:@"app_id"]];
        [sql matching:[NSArray arrayWithObject:@"app_id"]];

        NSString *statement = [sql statement];
        [self.connection execute:statement];

I make some fix in file ZIMSqlUpsertStatement.m

- (NSString *) statement {
    // Note: Because "INSERT OR REPLACE" requires prior knowledge of the table's columns to properly update a record,
    // this method for mimicing an upsert statement was chosen.  Therefore, always match against either the primary key
    // or a unique key.

    NSMutableString *sql = [[NSMutableString alloc] init];

    [sql appendFormat: @"UPDATE OR IGNORE %@ SET ", _table];

    NSMutableArray *set = [[NSMutableArray alloc] init];
    NSMutableArray *where = [[NSMutableArray alloc] init];

    for (NSString *column in _column) {
        if ([_compositeKey containsObject: column]) {
/////// MY FIX START /////// 
            if( [_column count] == 1 )
            {
                [set addObject: [NSString stringWithFormat: @"%@ = %@", column, [_column objectForKey: column]]];
            }            
/////// MY FIX END /////// 
            [where addObject: [NSString stringWithFormat: @"%@ = %@", column, [_column objectForKey: column]]];
        }
        else {
            [set addObject: [NSString stringWithFormat: @"%@ = %@", column, [_column objectForKey: column]]];
        }
    }

    [sql appendString: [set componentsJoinedByString: @", "]];
    [sql appendString: @" WHERE "];
    [sql appendString: [where componentsJoinedByString: @" AND "]];

    [sql appendString: @"; "];

    [sql appendFormat: @"INSERT OR IGNORE INTO %@ ", _table];

    [sql appendFormat: @"(%@) VALUES (%@)", [[_column allKeys] componentsJoinedByString: @", "], [[_column allValues] componentsJoinedByString: @", "]];

    [sql appendString: @";"];

    return sql;
}

[ziminji]

Thanks!