DbPatterns.fs

module DbExceptions

open System.Text.RegularExpressions

let (|GenericDbException|_|) (ex:exn) =
    match ex with
    | :? SqlException as ex -> Some(GenericDbException ex)
    | _ -> None

[<AutoOpen>]
module private CustomPatterns =
    let (|ExactSqlException|_|) = function
        | GenericDbException ex -> Some(ExactSqlException(ex.Number, ex))
        | _ -> None
    let (|NamedSqlException|_|) messagePart ex =
        match ex with
        | GenericDbException ex when ex.Message.Contains messagePart ->
            Some(NamedSqlException(ex.Number, ex))
        | _ -> None

let (|PrimaryKeyException|_|) = function
    | NamedSqlException "PRIMARY KEY" (2627, ex) -> Some(PrimaryKeyException ex)
    | _ -> None
let (|ForeignKeyConstraint|_|) = function
    | ExactSqlException (547, ex) -> Some (ForeignKeyConstraint ex)
    | _ -> None
let (|UniqueKeyException|_|) = function
    | NamedSqlException "UNIQUE KEY" ((2627, ex) | (2601, ex)) ->
        Some(UniqueKeyException ex)
    | _ -> None
let (|NullValueException|_|) (ex:exn) =
    match ex with
    | ExactSqlException (515, sqlEx) ->
        let m = Regex.Match(sqlEx.Message, "'[^']+'")
        if m.Success then Some(m.Value.Replace("'", "")) else None
    | :? System.Data.NoNullAllowedException as dataEx -> Some (dataEx.Message.Split(''').[1])
    | _ -> None
    |> Option.map(fun field -> NullValueException(Some field, ex))