如字段为 so.go.lie 查询上一级的方法为：ed,(reverse(substring_index(reverse(ed),'.',1))),'')
删除最后一个字符串的方法：
- LEFT(XXX,LENGTH(XXX)-1)
- SUBSTRING(XXX, 1,length(XXX)-1)
- TRIM(TRAILING ',' FROM XXX)
trim函数可以过滤指定的字符串：
完整格式：TRIM([{BOTH | LEADING | TRAILING} [remstr] FROM] str)
简化格式：TRIM([remstr FROM] str)
Returns the string str with all remstr prefixes or suffixes removed. If none of the specifiers BOTH, LEADING, or TRAILING is given, BOTH is assumed. remstr is optional and, if not specified, spaces are removed.
以下是代码片段：
|
1
2
3
4
5
6
7
8
|
mysql>
SELECT
TRIM(
' bar '
); //默认删除前后空格
->
'bar'
mysql>
SELECT
TRIM(LEADING
'，'
FROM
'，，barxxx'
); //删除指定首字符 如’，‘
->
'barxxx'
mysql>
SELECT
TRIM(BOTH
'，'
FROM
'，，bar，，，'
); //删除指定首尾字符
->
'bar'
mysql>
SELECT
TRIM(TRAILING
'，'
FROM
'barxxyz，，'
);
->
'barxxyz'
|