Improve comments and code readability

service/database/db-transactions.go

@@ -2,14 +2,17 @@ package database
 
 import "database/sql"
 
+// dbtransaction is a struct to represent an SQL transaction, it implements the DBTransaction interface
 type dbtransaction struct {
 	c *sql.Tx
 }
 
 func (tx *dbtransaction) Commit() error {
+	// Commit the SQL transaction
 	return tx.c.Commit()
 }
 
 func (tx *dbtransaction) Rollback() error {
+	// Rollback the SQL transaction
 	return tx.c.Rollback()
 }