想请教各位前辈
mysql> SELECT CAST(NOW() AS DATE) x1,
-> CAST(CAST(1-2 AS UNSIGNED) AS SIGNED) x2,
-> CAST(1-2 AS UNSIGNED) x3,
-> CAST(1 AS UNSIGNED) - 2.0 x4;
+

x3 -> Unsigned x4 -> Signedhttp://goo.gl/HvB5rg

都unsigned了还想要看到-1是怎样 用P档开完驾照考试吗