SELECT 1 FROM DUAL WHERE '14508070565939170465'=14508070565939172999 ;
SELECT 1 FROM DUAL WHERE '14508070565939170465'=14508070565939171213;
為啥上面兩條SQL 一句相等 一句不相等
uj5u.com熱心網友回復：
select '14508070565939170465'=14508070565939172352;
SELECT '14508070565939170465'=14508070565939172999;
SELECT '14508070565939170465'+0;
SELECT '14508070565939172352'+0;
SELECT '14508070565939172999'+0;
uj5u.com熱心網友回復：
mysql> select '14508070565939170465'+0;
+--------------------------+
| '14508070565939170465'+0 |
+--------------------------+
| 1.4508070565939171e19 |
+--------------------------+
1 row in set (0.00 sec)
mysql> select '14508070565939171213'+0;
+--------------------------+
| '14508070565939171213'+0 |
+--------------------------+
| 1.4508070565939171e19 |
+--------------------------+
1 row in set (0.00 sec)
mysql> select '14508070565939172999 '+0;
+---------------------------+
| '14508070565939172999 '+0 |
+---------------------------+
| 1.4508070565939173e19 |
+---------------------------+
1 row in set (0.00 sec)
mysql>
看出來了吧
uj5u.com熱心網友回復：
資料型別轉換導致的，= 兩邊的資料型別不一樣，這個會導致資料畸形轉換為一樣，然后再做比較轉載請註明出處，本文鏈接：https://www.uj5u.com/shujuku/113834.html
標籤：MySQL