refactor: simplify the code (#1670)

core/stores/builder/builder.go

@@ -48,19 +48,14 @@ func RawFieldNames(in interface{}, postgresSql ...bool) []string {
 			if strings.Contains(tagv, ",") {
 				tagv = strings.TrimSpace(strings.Split(tagv, ",")[0])
 			}
-			if tagv != "" {
+			if len(tagv) == 0 {
+				tagv = fi.Name
+			}
 			if pg {
 				out = append(out, tagv)
 			} else {
 				out = append(out, fmt.Sprintf("`%s`", tagv))
 			}
-			} else {
-				if pg {
-					out = append(out, fi.Name)
-				} else {
-					out = append(out, fmt.Sprintf("`%s`", fi.Name))
-				}
-			}
 		}
 	}