Feature: Support omit empty on dbtag (#12)

* Feature: Support omit empty on dbtag

* lint

Author: zagronitay

insert_test.go

@@ -8,10 +8,11 @@ import (
 )
 
 type insertModel struct {
-	IntField   int64 `db:"int_field"`
-	OtherValue string
-	SkipInsert bool   `goqux:"skip_insert"`
-	DbTag      string `db:"another_col_name"`
+	IntField       int64 `db:"int_field"`
+	OtherValue     string
+	SkipInsert     bool   `goqux:"skip_insert"`
+	DbTag          string `db:"another_col_name"`
+	DbTagOmitEmpty string `db:"another_col_name_omit,omitempty"`
 }
 
 func TestBuildInsert(t *testing.T) {
@@ -25,6 +26,13 @@ func TestBuildInsert(t *testing.T) {
 	}{
 		{
 			name:          "simple_insert",
+			values:        []any{insertModel{IntField: 5, DbTagOmitEmpty: "test"}},
+			expectedQuery: `INSERT INTO "insert_models" ("another_col_name", "another_col_name_omit", "int_field", "other_value") VALUES ($1, $2, $3, $4)`,
+			expectedArgs:  []interface{}{"", "test", int64(5), ""},
+			expectedError: nil,
+		},
+		{
+			name:          "simple_insert_ompitempty",
 			values:        []any{insertModel{IntField: 5}},
 			expectedQuery: `INSERT INTO "insert_models" ("another_col_name", "int_field", "other_value") VALUES ($1, $2, $3)`,
 			expectedArgs:  []interface{}{"", int64(5), ""},

struct.go

@@ -24,6 +24,8 @@ const (
 	defaultNow = "now"
 	// Same as default now but will inject time.Now().UTC()
 	defaultNowUtc = "now_utc"
+	// omitempty will skip the field if it is zero value
+	omitEmpty = ",omitempty"
 )
 
 func encodeValues(v any, skipType string, skipZeroValues bool) map[string]SQLValuer {
@@ -42,6 +44,12 @@ func encodeValues(v any, skipType string, skipZeroValues bool) map[string]SQLVal
 
 		columnName := strcase.ToSnake(f.Name)
 		if dbTag := f.Tag.Get(tagNameDb); dbTag != "" {
+			if strings.Contains(dbTag, omitEmpty) {
+				if value.IsZero() {
+					continue
+				}
+				dbTag = strings.ReplaceAll(dbTag, omitEmpty, "")
+			}
 			columnName = dbTag
 		}
 

update_test.go

@@ -9,8 +9,9 @@ import (
 )
 
 type updateModel struct {
-	IntField int
-	DbTag    string `db:"another_col_name"`
+	IntField       int
+	DbTag          string `db:"another_col_name"`
+	DbTagOmitEmpty string `db:"another_col_name_omit,omitempty"`
 }
 
 func TestBuildUpdate(t *testing.T) {
@@ -29,6 +30,13 @@ func TestBuildUpdate(t *testing.T) {
 			expectedArgs:  []interface{}{"test", int64(5)},
 			expectedError: nil,
 		},
+		{
+			name:          "simple_update",
+			dst:           updateModel{IntField: 5, DbTagOmitEmpty: "test"},
+			expectedQuery: `UPDATE "update_models" SET "another_col_name_omit"=$1,"int_field"=$2`,
+			expectedArgs:  []interface{}{"test", int64(5)},
+			expectedError: nil,
+		},
 		{
 			name:          "update_with_filters",
 			dst:           updateModel{IntField: 5},