add schema-handling to base.tableColumnNames(text)

src/main/resources/db/changelog/0-base/007-table-columns.sql

@@ -6,15 +6,31 @@
 --changeset michael.hoennig:table-columns-function endDelimiter:--//
 -- ----------------------------------------------------------------------------
 
-create or replace function base.tableColumnNames( tableName text )
+create or replace function base.tableColumnNames( ofTableName text )
     returns text
     stable
     language 'plpgsql' as $$
-declare columns text[];
+declare
+    tableName   text;
+    tableSchema text;
+    columns     text[];
 begin
+    tableSchema := CASE
+                       WHEN position('.' in ofTableName) > 0 THEN split_part(ofTableName, '.', 1)
+                       ELSE 'public'
+                   END;
+
+    tableName := CASE
+                     WHEN position('.' in ofTableName) > 0 THEN split_part(ofTableName, '.', 2)
+                     ELSE ofTableName
+        END;
+
     columns := (select array(select column_name::text
-                    from information_schema.columns
-                    where table_name = tableName));
+                               from information_schema.columns
+                              where table_name = tableName
+                                and table_schema = tableSchema));
+    assert cardinality(columns) > 0, 'cannot determine columns of table ' || ofTableName ||
+                                     '("' || tableSchema || '"."' || tableName || '")';
     return array_to_string(columns, ', ');
 end; $$
 --//