*: fix the bug of create user

Author: acekingke

controllers/mysqluser_controller.go

@@ -180,6 +180,14 @@ func (r *MysqlUserReconciler) reconcileUserInDB(ctx context.Context, mysqlUser *
 	if password == "" {
 		return fmt.Errorf("the MySQL user's password must not be empty")
 	}
+	var exists bool
+	var err2 error
+	if exists, err2 = internal.CheckUserExists(sqlRunner, mysqlUser.Spec.User); err2 != nil {
+		return fmt.Errorf("failed to check if user exists: %v", err2)
+	}
+	if !exists {
+		mysqlUser.Status.Revision = ""
+	}
 	// Remove allowed hosts for user.
 	toRemove := utils.StringDiffIn(mysqlUser.Status.AllowedHosts, mysqlUser.Spec.Hosts)
 	for _, host := range toRemove {

internal/sql_runner.go

@@ -320,6 +320,19 @@ func GetGlobalVariable(sqlRunner SQLRunner, param string, val interface{}) error
 	return sqlRunner.QueryRowContext(ctx, NewQuery("select @@global.?", param), val)
 }
 
+// Check user exists or not.
+func CheckUserExists(sqlRunner SQLRunner, userName string) (bool, error) {
+	var rows *sql.Rows
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	rows, err := sqlRunner.QueryRowsContext(ctx, NewQuery("select user from mysql.user where user =?", userName))
+	if err != nil {
+		return false, err
+	}
+	defer rows.Close()
+	return rows.Next(), nil
+}
+
 func CheckProcesslist(sqlRunner SQLRunner) (bool, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()