migrate from github

internal/repository/document_version_repo/get_latest.go

@@ -0,0 +1,41 @@
+package document_version_repo
+
+import (
+	"github.com/XingfenD/yoresee_doc/internal/model"
+	"gorm.io/gorm"
+)
+
+type DocumentVersionGetLastedOperation struct {
+	repo  *DocumentVersionRepository
+	docID int64
+	tx    *gorm.DB
+}
+
+func (r *DocumentVersionRepository) GetLasted(docID int64) *DocumentVersionGetLastedOperation {
+	return &DocumentVersionGetLastedOperation{
+		repo:  r,
+		docID: docID,
+	}
+}
+
+func (op *DocumentVersionGetLastedOperation) WithTx(tx *gorm.DB) *DocumentVersionGetLastedOperation {
+	op.tx = tx
+	return op
+}
+
+func (op *DocumentVersionGetLastedOperation) Exec() (int64, error) {
+	if op.tx == nil {
+		op.tx = op.repo.db
+	}
+
+	var maxVersion int64
+	err := op.tx.Model(&model.DocumentVersion{}).
+		Where("document_id = ?", op.docID).
+		Select("COALESCE(MAX(version), 0)").
+		Scan(&maxVersion).Error
+	if err != nil {
+		return 0, err
+	}
+
+	return maxVersion, nil
+}