Add: update tag info

pkg/database/method_tag.go

@@ -1,5 +1,7 @@
 package database
 
+import "errors"
+
 func (database *Database) InsertTag(tag string, description string) (*Tag, error) {
 	result, err := database.stmt.insertTag.Exec(tag, description)
 	if err != nil {
@@ -38,3 +40,18 @@ func (database *Database) GetTags() ([]Tag, error) {
 	}
 	return tags, nil
 }
+
+func (database *Database) UpdateTag(tag *Tag) (*Tag, error) {
+	result, err := database.stmt.updateTag.Exec(tag.Name, tag.Description, tag.ID)
+	if err != nil {
+		return nil, err
+	}
+	rowsAffected, err := result.RowsAffected()
+	if err != nil {
+		return nil, err
+	}
+	if rowsAffected == 0 {
+		return nil, errors.New("No rows affected")
+	}
+	return database.GetTag(tag.ID)
+}

pkg/database/sql_stmt.go

@@ -176,6 +176,8 @@ var getTagQuery = `SELECT id, name, description FROM tags WHERE id = ? LIMIT 1;`
 
 var getTagsQuery = `SELECT id, name, description FROM tags;`
 
+var updateTagQuery = `UPDATE tags SET name = ?, description = ? WHERE id = ?;`
+
 type Stmt struct {
 	initFilesTable     *sql.Stmt
 	initFoldersTable   *sql.Stmt
@@ -211,6 +213,7 @@ type Stmt struct {
 	insertTag          *sql.Stmt
 	getTag             *sql.Stmt
 	getTags            *sql.Stmt
+	updateTag          *sql.Stmt
 }
 
 func NewPreparedStatement(sqlConn *sql.DB) (*Stmt, error) {
@@ -485,5 +488,11 @@ func NewPreparedStatement(sqlConn *sql.DB) (*Stmt, error) {
 		return nil, err
 	}
 
+	// init updateTag
+	stmt.updateTag, err = sqlConn.Prepare(updateTagQuery)
+	if err != nil {
+		return nil, err
+	}
+
 	return stmt, err
 }