Schema support for PostgreSQL backend

Author: arrowd

persistent-postgresql/Database/Persist/Postgresql.hs

@@ -437,7 +437,7 @@ createBackend logFunc serverVersion smap conn =
         , connCommit     = const $ PG.commit   conn
         , connRollback   = const $ PG.rollback conn
         , connEscapeFieldName = escapeF
-        , connEscapeTableName = escapeE . getEntityDBName
+        , connEscapeTableName = \entDef -> prependSchemaAndEscape entDef $ getEntityDBName entDef
         , connEscapeRawName = escape
         , connNoLimit    = "LIMIT ALL"
         , connRDBMS      = "postgresql"
@@ -760,7 +760,8 @@ getColumns :: (Text -> IO Statement)
            -> EntityDef -> [Column]
            -> IO [Either Text (Either Column (ConstraintNameDB, [FieldNameDB]))]
 getColumns getter def cols = do
-    let sqlv = T.concat
+    let tableSchema = fromMaybe "current_schema()" (getEntityDBSchema def)
+        sqlv = T.concat
             [ "SELECT "
             , "column_name "
             , ",is_nullable "
@@ -772,7 +773,7 @@ getColumns getter def cols = do
             , ",character_maximum_length "
             , "FROM information_schema.columns "
             , "WHERE table_catalog=current_database() "
-            , "AND table_schema=current_schema() "
+            , "AND table_schema=" <> tableSchema <> " "
             , "AND table_name=? "
             ]
 
@@ -797,7 +798,7 @@ getColumns getter def cols = do
             , "information_schema.table_constraints AS k "
             , "WHERE c.table_catalog=current_database() "
             , "AND c.table_catalog=k.table_catalog "
-            , "AND c.table_schema=current_schema() "
+            , "AND c.table_schema=" <> tableSchema <> " "
             , "AND c.table_schema=k.table_schema "
             , "AND c.table_name=? "
             , "AND c.table_name=k.table_name "
@@ -1338,6 +1339,12 @@ showAlter table (DropReference cname) = T.concat
     , escapeC cname
     ]
 
+prependSchemaAndEscape :: EntityDef -> EntityNameDB -> Text
+prependSchemaAndEscape entDef entDBName = case getEntityDBSchema entDef of
+    Nothing -> escapeE entDBName
+    Just "public" -> escapeE entDBName
+    Just schema -> escape schema <> "." <> escapeE entDBName
+
 -- | Get the SQL string for the table that a PeristEntity represents.
 -- Useful for raw SQL queries.
 tableName :: (PersistEntity record) => record -> Text
@@ -1574,7 +1581,7 @@ mockMigration mig = do
                 , connCommit = undefined
                 , connRollback = undefined
                 , connEscapeFieldName = escapeF
-                , connEscapeTableName = escapeE . getEntityDBName
+                , connEscapeTableName = \entDef -> prependSchemaAndEscape entDef $ getEntityDBName entDef
                 , connEscapeRawName = escape
                 , connNoLimit = undefined
                 , connRDBMS = undefined