val intToSql : int -> string
val intFromSql : string -> int
val stringToSql : string -> string
val stringFromSql : string -> string
val timestampToSql : timestamp -> string
val intToSql : int -> string
val intFromSql : string -> int
val stringToSql : string -> string
val stringFromSql : string -> string
val timestampToSql : timestamp -> string