1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
{-# LANGUAGE CPP,DeriveDataTypeable #-}
{-| `SqlError' type for a variety of DB specific error conditions,
with appropriate `Show', `Typeable', and `Exception' instances.
-}
module DB.HSQL.Error(SqlError(..)) where
import Control.Exception(Exception(..),SomeException(..))
import Data.Dynamic(Typeable,TyCon,mkTyCon3,cast)
import DB.HSQL.Type(SqlType)
-- |
data SqlError
= SqlError
{ seState :: String
, seNativeError :: Int
, seErrorMsg :: String
} -- ^ generic error condition, with further specification
| SqlNoMoreData -- ^ no more data was available
| SqlInvalidHandle -- ^ requested handle is invalid
| SqlStillExecuting -- ^ connection is blocked by running transaction
| SqlNeedMoreData -- ^ more data is needed, e.g. additional connection
-- specs
| SqlBadTypeCast
{ seFieldName :: String
, seFieldType :: SqlType
} -- ^ requested field can't be converted to requested type
| SqlFetchNull
{ seFieldName :: String } -- ^ requested field returns NULL
| SqlUnknownField
{ seFieldName :: String } -- ^ requested field isn't known
| SqlUnsupportedOperation -- ^ requested operation isn't supported
| SqlClosedHandle -- ^ referenced handle is already closed
#ifdef __GLASGOW_HASKELL__
deriving (Eq,Ord,Typeable)
#else
deriving (Eq,Ord)
instance Typeable SqlError where
typeOf _ = mkAppTy sqlErrorTc []
#endif
-- | The `TyCon' of `SqlError'.
sqlErrorTc :: TyCon
sqlErrorTc = mkTyCon3 "DB.HSQL" "Error" "SqlError"
-- |
instance Show SqlError where
showsPrec _ (SqlError{seErrorMsg=msg}) = showString msg
showsPrec _ SqlNoMoreData =
showString "No more data was available"
showsPrec _ SqlInvalidHandle = showString "Invalid handle"
showsPrec _ SqlStillExecuting = showString "Still executing"
showsPrec _ SqlNeedMoreData =
showString "More data is needed, e.g. additional connection specs"
showsPrec _ (SqlBadTypeCast name tp) =
showString ("The type of "++name++" field can't be converted to "
++show tp++" type")
showsPrec _ (SqlFetchNull name) =
showString ("The value of "++name++" field is null")
showsPrec _ (SqlUnknownField name) =
showString ("Unknown field name: "++name)
showsPrec _ SqlUnsupportedOperation = showString "Unsupported operation"
showsPrec _ SqlClosedHandle =
showString "The referenced handle is already closed"
-- |
instance Exception SqlError where
toException = SomeException
fromException (SomeException exception) =
cast exception
|
