Include "enum" field in column details

src/PgStructure.hs

@@ -11,6 +11,7 @@ import Data.Maybe (mapMaybe)
 import Control.Applicative ( (<*>) )
 
 import qualified Data.ByteString.Lazy as BL
+import Data.List.Split (splitOn)
 
 import qualified Data.Aeson as JSON
 
@@ -47,6 +48,7 @@ data Column = Column {
 , colMaxLen :: Maybe Int
 , colPrecision :: Maybe Int
 , colDefault :: Maybe String
+, colEnum :: Maybe [String]
 } deriving (Show)
 
 instance JSON.ToJSON Column where
@@ -59,7 +61,8 @@ instance JSON.ToJSON Column where
     , "updatable" .= colUpdatable c
     , "maxLen"    .= colMaxLen c
     , "precision" .= colPrecision c
-    , "default"   .= colDefault c ]
+    , "default"   .= colDefault c
+    , "enum"      .= colEnum c ]
 
 data TableOptions = TableOptions {
   tblOptcolumns :: [Column]
@@ -91,17 +94,36 @@ tables s conn = do
 columns :: String -> String -> Connection -> IO [Column]
 columns s t conn = do
   r <- quickQuery conn
-        "select table_schema, table_name, column_name, ordinal_position,\
-        \       is_nullable, data_type, is_updatable,\
-        \       character_maximum_length, numeric_precision,\
-        \       column_default\
-        \  from information_schema.columns\
-        \ where table_schema = ?\
-        \   and table_name = ?" [toSql s, toSql t]
+    " select info.table_schema as schema, info.table_name as table_name,               \
+    \        info.column_name as name, info.ordinal_position as position,              \
+    \        info.is_nullable as nullable, info.data_type as col_type,                 \
+    \        info.is_updatable as updatable, info.character_maximum_length as max_len, \
+    \        info.numeric_precision as precision, info.column_default as default_value,\
+    \        array_to_string(enum_info.vals, ',') as enum                              \
+    \   from (                                                                         \
+    \     select table_schema, table_name, column_name, ordinal_position,              \
+    \            is_nullable, data_type, is_updatable,                                 \
+    \            character_maximum_length, numeric_precision,                          \
+    \            column_default, udt_name                                              \
+    \       from information_schema.columns                                            \
+    \      where table_schema = ?                                                      \
+    \        and table_name = ?                                                        \
+    \   ) as info                                                                      \
+    \   left outer join (                                                              \
+    \     select n.nspname as s,                                                       \
+    \            t.typname as n,                                                       \
+    \            array_agg(e.enumlabel) as vals                                        \
+    \     from pg_type t                                                               \
+    \        join pg_enum e on t.oid = e.enumtypid                                     \
+    \        join pg_catalog.pg_namespace n ON n.oid = t.typnamespace                  \
+    \     group by s, n                                                                \
+    \   ) as enum_info                                                                 \
+    \   on (info.udt_name = enum_info.n)                                               \
+    \order by position" [toSql s, toSql t]
   return $ mapMaybe mkColumn r
 
   where
-    mkColumn [schema, table, name, pos, nullable, colT, updatable, maxlen, precision, defVal] =
+    mkColumn [schema, table, name, pos, nullable, colT, updatable, maxlen, precision, defVal, enum] =
       Just $ Column (fromSql schema)
         (fromSql table)
         (fromSql name)
@@ -112,6 +134,7 @@ columns s t conn = do
         (fromSql maxlen)
         (fromSql precision)
         (fromSql defVal)
+        (splitOn "," <$> fromSql enum)
     mkColumn _ = Nothing
 
 printTables :: String -> Connection -> IO BL.ByteString