proc alterAddForeignKey(column: Column; table: Table): string {.
    ...raises: [KeyError], tags: [], forbids: [].}

proc createColumnString(table: Table; column: Column): string {.
    ...raises: [KeyError, DbError], tags: [], forbids: [].}

proc createForeignKey(table: Table; column: Column): string {.
    ...raises: [KeyError], tags: [], forbids: [].}

proc createIndexString(table: Table; column: Column): string {....raises: [],
    tags: [], forbids: [].}