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法律研究我們可以使用 MySQL 中的哪些函式來更改字串的字元大小寫？
我們可以使用 LCASE() 和 LOWER() 函式將字串的字元大小寫更改為小寫，使用 UCASE() 和 UPPER() 函式將字串的字元大小寫更改為大寫。
示例
mysql> Select LCASE('NEW DELHI');
+--------------------+
| LCASE('NEW DELHI') |
+--------------------+
| new delhi |
+--------------------+
1 row in set (0.00 sec)
mysql> Select LOWER('NEW DELHI');
+--------------------+
| LOWER('NEW DELHI') |
+--------------------+
| new delhi |
+--------------------+
1 row in set (0.00 sec)
mysql> Select UCASE('new delhi');
+--------------------+
| UCASE('new delhi') |
+--------------------+
| NEW DELHI |
+--------------------+
1 row in set (0.00 sec)
mysql> Select UPPER('new delhi');
+--------------------+
| UPPER('new delhi') |
+--------------------+
| NEW DELHI |
+--------------------+
1 row in set (0.00 sec)我們還可以將這些函式與表中的列一起使用。例如，假設我們想更改輸出中的某個列中的值的字元大小寫，那麼對“Student”表的以下查詢可以展示如何更改 -
mysql> Select Name, UCASE(Name) from student; +---------+-------------+ | Name | UCASE(Name) | +---------+-------------+ | Gaurav | GAURAV | | Aarav | AARAV | | Harshit | HARSHIT | | Gaurav | GAURAV | | Yashraj | YASHRAJ | +---------+-------------+ 5 rows in set (0.00 sec) mysql> Select Name, LCASE(Name) from student; +---------+-------------+ | Name | LCASE(Name) | +---------+-------------+ | Gaurav | gaurav | | Aarav | aarav | | Harshit | harshit | | Gaurav | gaurav | | Yashraj | yashraj | +---------+-------------+ 5 rows in set (0.00 sec) mysql> Select Name, UPPER(Name) from student; +---------+-------------+ | Name | UPPER(Name) | +---------+-------------+ | Gaurav | GAURAV | | Aarav | AARAV | | Harshit | HARSHIT | | Gaurav | GAURAV | | Yashraj | YASHRAJ | +---------+-------------+ 5 rows in set (0.00 sec) mysql> Select Name, LOWER(Name) from student; +---------+-------------+ | Name | LOWER(Name) | +---------+-------------+ | Gaurav | gaurav | | Aarav | aarav | | Harshit | harshit | | Gaurav | gaurav | | Yashraj | yashraj | +---------+-------------+ 5 rows in set (0.00 sec)
更新時間：04-Feb-2020
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