php 是否有将字符串转换为小写的 MySQL 命令？
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Is there a MySQL command to convert a string to lowercase?
提问by Thomas Owens
I have a MySQL database of keywords that are presently mixed-case. However, I want to convert them all to lowercase. Is there an easy command to do this, either using MySQL or MySQL and PHP?
我有一个目前大小写混合的关键字的 MySQL 数据库。但是，我想将它们全部转换为小写。是否有一个简单的命令来执行此操作，无论是使用 MySQL 还是 MySQL 和 PHP？
回答by Paul Dixon
UPDATE table SET colname=LOWER(colname);
回答by Jon Grant
Yes, the function is LOWER() or LCASE() (they both do the same thing).
是的，函数是 LOWER() 或 LCASE() （它们都做同样的事情）。
For example:
例如：
select LOWER(keyword) from my_table
回答by Greg
SELECT LOWER(foo) AS foo FROM bar
SELECT LOWER(foo) AS foo FROM bar
回答by dmanxiii
You can use the functions LOWER() or LCASE().
您可以使用函数 LOWER() 或 LCASE()。
These can be used both on columns or string literals. e.g.
这些可以用于列或字符串文字。例如
SELECT LOWER(column_name) FROM table a;
or
或者
SELECT column_name FROM table a where column = LOWER('STRING')
LCASE() can be substituted for LOWER() in both examples.
在两个示例中，LCASE() 都可以替换为 LOWER()。
回答by myplacedk
Did you try looking it up? Google, manual...
你试过查一下吗？谷歌，手动...
http://dev.mysql.com/doc/refman/5.1/en/string-functions.html#function_lower
http://dev.mysql.com/doc/refman/5.1/en/string-functions.html#function_lower
mysql> SELECT LOWER('QUADRATICALLY');
-> 'quadratically'
回答by Vi8L
Simply use:
只需使用：
UPDATE `tablename` SET `colnameone`=LOWER(`colnameone`);
or
或者
UPDATE `tablename` SET `colnameone`=LCASE(`colnameone`);
Both functions will work the same.
这两个功能的工作方式相同。
回答by HD FrenchFeast
Interesting to note that the field name is renamed and if you reference it in a function, you will not get its value unless you give him an alias (that can be its own name)
有趣的是，字段名被重命名，如果你在函数中引用它，除非你给他一个别名（可以是它自己的名字），否则你不会得到它的值
Example: I use a function to dynamically get a field name value:
示例：我使用一个函数来动态获取字段名称值：
function ColBuilder ($field_name) {
…
While ($result = DB_fetch_array($PricesResult)) {
$result[$field_name]
}
…
}
my query being: SELECT LOWER(itemID), … etc..
我的查询是：SELECT LOWER(itemID), ... 等等。
needed to be changed to: SELECT LOWER(itemID) as itemID, … etc..
需要更改为：SELECT LOWER(itemID) as itemID，...等。
回答by uma
use LOWERfunction to convert data or string in lower case.
使用LOWER函数将数据或字符串转换为小写。
select LOWER(username) from users;
or
或者
select * from users where LOWER(username) = 'vrishbh';
回答by Rodent43
I believe in php you can use
我相信你可以使用 php
strtolower()
so you could make a php to read all the entries in the table then use that command to print them back as lower case
所以你可以制作一个 php 来读取表中的所有条目，然后使用该命令将它们打印回小写
