The diff query generator

2 files changed, 48 insertions, 1 deletions

diff --git a/DAL/DB/CRUD.go b/DAL/DB/CRUD.go
index b466d3c..52268df 100644
--- a/DAL/DB/CRUD.go
+++ b/DAL/DB/CRUD.go
@@ -10,6 +10,21 @@ type DataTable[T any] struct {
 	TableName string
 }
 
+func (base *DataTable[T]) GetSimilarFieldsQuery(ref T, fields []string) (string, error) {
+	var structFields = base.getFieldsMap()
+	var value = reflect.ValueOf(ref)
+	var filterMap = make(map[string]any)
+	for _, v := range fields {
+		var fieldIndex, exists = structFields[v]
+		if !exists {
+			return "", fmt.Errorf("Failed to create a query for the object: there is no such field as %s in %s", v, reflect.TypeFor[T]().Name())
+		}
+		filterMap[v] = value.Field(fieldIndex).Interface()
+	}
+	fmt.Println(filterMap)
+	return base.formQueryWithFilters(filterMap), nil
+}
+
 // Filters are stored as KVP where the field is the key and the value is the filter
 func (base *DataTable[T]) formQueryWithFilters(filters map[string]any) string {
 	if len(filters) == 0 {
@@ -67,3 +82,17 @@ func (base *DataTable[T]) getFields() []string {
 	}
 	return outp
 }
+
+func (base *DataTable[T]) getFieldsMap() map[string]int {
+	var zero T
+	var outp = make(map[string]int)
+	for i, f := range reflect.VisibleFields(reflect.TypeOf(zero)) {
+		var tag, exists = f.Tag.Lookup("sql")
+		if exists {
+			outp[tag] = i
+		} else {
+			outp[f.Name] = i
+		}
+	}
+	return outp
+}
diff --git a/DAL/DB/CRUD_test.go b/DAL/DB/CRUD_test.go
index 3b60aa0..d6fba1f 100644
--- a/DAL/DB/CRUD_test.go
+++ b/DAL/DB/CRUD_test.go
@@ -34,4 +34,22 @@ func TestFilteredSelectRequestForm(t *testing.T) {
 	}
 }
 
-
+func TestSearchSimilarElementQuery(t *testing.T) {
+	var reference = testDataType {
+		Id: 10,
+		Name: "physick",
+		Data: time.Now(),
+	}
+	var expected = "SELECT (Id, username, Data) FROM DataTable WHERE (Id = 10 AND username = 'physick');"
+	var request, err = testDataTable.GetSimilarFieldsQuery(reference, []string {
+		"Id",
+		"username",
+	})
+	if err != nil {
+		t.Error(err.Error())
+		return
+	}
+	if request != expected {
+		t.Errorf("Incorrect select query. \n Expected: '%s' \n Got:      '%s'", expected, request)
+	}
+}