Remove duplicate records with multi value fields

pkg/codegen/assets/store_rdbms.gen.go.tpl

@@ -198,6 +198,11 @@ func (s Store) {{ unexport "fetchFullPageOf" $.Types.Plural  }} (
 		} else {
 			tryQuery = q
 		}
+		{{ if .RDBMS.CustomPreLoadProcessor }}
+		if tryQuery, err = s.{{ unexport $.Types.Singular }}PreLoadProcessor(tryQuery); err != nil {
+			return
+		}
+		{{- end}}
 
 		if limit > 0 {
 			// fetching + 1 so we know if there are more items

pkg/codegen/store.go

@@ -86,6 +86,7 @@ type (
 		CustomFilterConverter   bool `yaml:"customFilterConverter"`
 		CustomSortConverter     bool `yaml:"customSortConverter"`
 		CustomCursorCollector   bool `yaml:"customCursorCollector"`
+		CustomPreLoadProcessor  bool `yaml:"customPreLoadProcessor"`
 		CustomPostLoadProcessor bool `yaml:"customPostLoadProcessor"`
 		CustomEncoder           bool `yaml:"customEncoder"`
 

store/compose_records.yaml

@@ -56,6 +56,7 @@ rdbms:
   customFilterConverter: true
   customSortConverter: true
   customCursorCollector: true
+  customPreLoadProcessor: true
   customPostLoadProcessor: true
   mapFields:
     ModuleID:  { column: module_id }

store/rdbms/compose_records.gen.go

@@ -73,6 +73,10 @@ func (s Store) fetchFullPageOfComposeRecords(
 			tryQuery = q
 		}
 
+		if tryQuery, err = s.composeRecordPreLoadProcessor(tryQuery); err != nil {
+			return
+		}
+
 		if limit > 0 {
 			// fetching + 1 so we know if there are more items
 			// we can fetch (next-page cursor)

store/rdbms/compose_records.go

@@ -221,6 +221,10 @@ func (s Store) composeRecordsPageNavigation(
 				q = supPageQuery.Where(cursorCond(cursor))
 			}
 
+			if q, err = s.composeRecordPreLoadProcessor(q); err != nil {
+				return
+			}
+
 			rows, err = s.Query(ctx, q)
 			if err != nil {
 				return err
@@ -623,6 +627,16 @@ func (s Store) composeRecordPostLoadProcessor(ctx context.Context, m *types.Modu
 	return nil
 }
 
+func (s Store) composeRecordPreLoadProcessor(q squirrel.SelectBuilder) (squirrel.SelectBuilder, error) {
+	// When filtering over multi value record values we can get multiple rows of the same record
+	// causing it to show as a duplicate in the output.
+	// This partitioning removes any duplicate rows (rows where the index is not 1).
+	return squirrel.Select(s.composeRecordColumns()...).
+		PlaceholderFormat(s.config.PlaceholderFormat).
+		FromSelect(q.Column("row_number() over (partition by id) as pp_rn"), "base").
+		Where("pp_rn = 1"), nil
+}
+
 func (s Store) composeRecordsSorter(m *types.Module, q squirrel.SelectBuilder, sort filter.SortExprSet) (squirrel.SelectBuilder, error) {
 	var (
 		sortable = s.sortableComposeRecordColumns()