l> SELECT @var1, @var2 := @var1;\n        -> 1, 1\nmysql> SELECT @var1, @var2;\n        -> 1, 1\n\nmysql> SELECT @var1:=COUNT(*) FROM t1;\n        -> 4\nmysql> SELECT @var1;\n        -> 4\n','https://dev.mysql.com/doc/refman/8.0/en/assignment-operators.html');