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Merge pull request #594 from ruslantalpa/multiple_fks

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Fix include entities from the same parent table using two different foreign keys
This commit is contained in:
Joe Nelson
2016-05-17 22:54:12 -07:00
parent 2ac3ad9e37 9e6542680b
commit 36a6b10d0d
7 changed files with 57 additions and 33 deletions
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src/PostgREST/QueryBuilder.hs
+20 -32
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@@ -36,17 +36,17 @@ import qualified Data.Aeson as JSON
import Data.Int (Int64)
import PostgREST.RangeQuery (NonnegRange, rangeLimit, rangeOffset)
import Control.Error (note, fromMaybe, mapMaybe)
import Control.Error (note, fromMaybe)
import Data.Functor.Contravariant (contramap)
import qualified Data.HashMap.Strict as HM
import Data.List (find, (\\))
import Data.List (find)
import Data.Monoid ((<>))
import Data.Text (Text, intercalate, unwords, replace, isInfixOf, toLower, split)
import qualified Data.Text as T (map, takeWhile)
import qualified Data.Text.Encoding as T
import Data.String.Conversions (cs)
import Control.Applicative ((<|>))
import Control.Monad (join)
-- import Control.Monad (join)
import Data.Tree (Tree(..))
import qualified Data.Vector as V
import PostgREST.Types
@@ -182,25 +182,18 @@ addRelations schema allRelations parentNode node@(Node readNode@(query, (name, _
where n `colMatches` rc = (cs ("^" <> rc <> "_?(?:|[iI][dD]|[fF][kK])$") :: BS.ByteString) =~ (cs n :: BS.ByteString)
addJoinConditions :: Schema -> ReadRequest -> Either Text ReadRequest
addJoinConditions schema (Node (query, (n, r, a)) forest) =
addJoinConditions schema (Node nn@(query, (n, r, a)) forest) =
case r of
Nothing -> Node (updatedQuery, (n,r,a)) <$> updatedForest -- this is the root node
Just rel@Relation{relType=Child} -> Node (addCond updatedQuery (getJoinConditions rel),(n,r,a)) <$> updatedForest
Just Relation{relType=Parent} -> Node (updatedQuery, (n,r,a)) <$> updatedForest
Nothing -> Node nn <$> updatedForest -- this is the root node
Just rel@Relation{relType=Child} -> Node (addCond query (getJoinConditions rel),(n,r,a)) <$> updatedForest
Just Relation{relType=Parent} -> Node nn <$> updatedForest
Just rel@Relation{relType=Many, relLTable=(Just linkTable)} ->
Node (qq, (n, r, a)) <$> updatedForest
where
query' = addCond updatedQuery (getJoinConditions rel)
query' = addCond query (getJoinConditions rel)
qq = query'{from=tableName linkTable : from query'}
_ -> Left "unknown relation"
where
-- add parentTable and parentJoinConditions to the query
updatedQuery = foldr (flip addCond) query parentJoinConditions
where
parentJoinConditions = map (getJoinConditions . snd) parents
parents = mapMaybe (getParents . rootLabel) forest
getParents (_, (tbl, Just rel@Relation{relType=Parent}, _)) = Just (tbl, rel)
getParents _ = Nothing
updatedForest = mapM (addJoinConditions schema) forest
addCond query' con = query'{flt_=con ++ flt_ query'}
@@ -288,8 +281,8 @@ requestToQuery schema (DbRead (Node (Select colSelects tbls conditions ord, (nod
query = unwords [
"SELECT ", intercalate ", " (map (pgFmtSelectItem qi) colSelects ++ selects),
"FROM ", intercalate ", " (map (fromQi . toQi) tbls),
unwords (map joinStr joins),
("WHERE " <> intercalate " AND " ( map (pgFmtCondition qi ) localConditions )) `emptyOnNull` localConditions,
unwords joins,
("WHERE " <> intercalate " AND " ( map (pgFmtCondition qi ) conditions )) `emptyOnNull` conditions,
orderF (fromMaybe [] ord)
]
orderF ts =
@@ -304,17 +297,8 @@ requestToQuery schema (DbRead (Node (Select colSelects tbls conditions ord, (nod
<> (cs.show) (otDirection t) <> " "
<> maybe "" (cs.show) (otNullOrder t) <> " "
(joins, selects) = foldr getQueryParts ([],[]) forest
parentTables = map snd joins
parentConditions = join $ map (( `filter` conditions ) . filterParentConditions) parentTables
localConditions = conditions \\ parentConditions
joinStr :: (SqlFragment, TableName) -> SqlFragment
joinStr (sql, t) = "LEFT OUTER JOIN " <> sql <> " ON " <>
intercalate " AND " ( map (pgFmtCondition qi ) joinConditions )
where
joinConditions = filter (filterParentConditions t) conditions
filterParentConditions parentTable (Filter _ _ (VForeignKey (QualifiedIdentifier "" t) _)) = parentTable == t
filterParentConditions _ _ = False
getQueryParts :: Tree ReadNode -> ([(SqlFragment, TableName)], [SqlFragment]) -> ([(SqlFragment,TableName)], [SqlFragment])
getQueryParts :: Tree ReadNode -> ([SqlFragment], [SqlFragment]) -> ([SqlFragment], [SqlFragment])
getQueryParts (Node n@(_, (name, Just Relation{relType=Child,relTable=Table{tableName=table}}, alias)) forst) (j,s) = (j,sel:s)
where
sel = "COALESCE(("
@@ -322,10 +306,15 @@ requestToQuery schema (DbRead (Node (Select colSelects tbls conditions ord, (nod
<> "FROM (" <> subquery <> ") " <> pgFmtIdent table
<> "), '[]') AS " <> pgFmtIdent (fromMaybe name alias)
where subquery = requestToQuery schema (DbRead (Node n forst))
getQueryParts (Node n@(_, (name, Just Relation{relType=Parent,relTable=Table{tableName=table}}, alias)) forst) (j,s) = (joi:j,sel:s)
getQueryParts (Node n@(_, (name, Just r@Relation{relType=Parent,relTable=Table{tableName=table}}, alias)) forst) (j,s) = (joi:j,sel:s)
where
sel = "row_to_json(" <> pgFmtIdent table <> ".*) AS " <> pgFmtIdent (fromMaybe name alias)
joi = ("( " <> subquery <> " ) AS " <> pgFmtIdent table, table)
node_name = fromMaybe name alias
local_table_name = table <> "_" <> node_name
replaceTableName localTableName (Filter a b (VForeignKey (QualifiedIdentifier "" _) c)) = Filter a b (VForeignKey (QualifiedIdentifier "" localTableName) c)
replaceTableName _ x = x
sel = "row_to_json(" <> pgFmtIdent local_table_name <> ".*) AS " <> pgFmtIdent node_name
joi = " LEFT OUTER JOIN ( " <> subquery <> " ) AS " <> pgFmtIdent local_table_name <>
" ON " <> intercalate " AND " ( map (pgFmtCondition qi . replaceTableName local_table_name) (getJoinConditions r) )
where subquery = requestToQuery schema (DbRead (Node n forst))
getQueryParts (Node n@(_, (name, Just Relation{relType=Many,relTable=Table{tableName=table}}, alias)) forst) (j,s) = (j,sel:s)
where
@@ -361,7 +350,6 @@ requestToQuery schema (DbMutate (Update mainTbl (PayloadJSON (UniformObjects row
Nothing -> undefined
where
qi = QualifiedIdentifier schema mainTbl
requestToQuery schema (DbMutate (Delete mainTbl conditions)) =
query
where