codegen: add generator for soft-deletion

pkg/schema/table.go

@@ -61,3 +61,18 @@ func (t Table) HasAutoTimestamps() (hasCreatedAt bool, hasUpdatedAt bool) {
 	}
 	return
 }
+
+// HasSoftDelete reports whether this table supports soft-deletion, i.e., whether it has both
+// an "is_deleted" and a "deleted_at" column.
+func (t Table) HasSoftDelete() bool {
+	var hasIsDeleted, hasDeletedAt bool
+	for _, c := range t.Columns {
+		if c.Name == "is_deleted" && c.Type == "integer" {
+			hasIsDeleted = true
+		}
+		if c.Name == "deleted_at" && c.Type == "integer" {
+			hasDeletedAt = true
+		}
+	}
+	return hasIsDeleted && hasDeletedAt
+}