Tsql 即使存在子字符串，CHARINDEX也返回0

我正在尝试提取列之一的子字符串

SELECT PT.col1 AS MyColumn
    ,(
        CASE WHEN CHARINDEX(PT.col1, '$') > 0
             THEN SUBSTRING(PT.col1, CHARINDEX(PT.col1, '$') + 1, 
                  LEN(PT.col1) - CHARINDEX(PT.col1, '$') - 1)
             ELSE ''
        END 
     )
,T1.col2
,PT.col3
,T1.col4
,T1.col5
 //...

我得到的是所有行的空字符串。我试图只显示

$”字符的索引，但得到的结果是

0`

PT.col1

的值看起来像

法语（加拿大）$fr CA

，

葡萄牙语（巴西）$PT BR

---

我遗漏了什么吗？

您必须切换参数：

SELECT CHARINDEX('a$bc', '$') AS Wrong, CHARINDEX('$', 'a$bc') AS Ok
/*
Wrong       Ok
----------- -----------
0           2
*/

---

您必须切换参数：

SELECT CHARINDEX('a$bc', '$') AS Wrong, CHARINDEX('$', 'a$bc') AS Ok
/*
Wrong       Ok
----------- -----------
0           2
*/

---

您必须切换参数：

SELECT CHARINDEX('a$bc', '$') AS Wrong, CHARINDEX('$', 'a$bc') AS Ok
/*
Wrong       Ok
----------- -----------
0           2
*/

---

您必须切换参数：

SELECT CHARINDEX('a$bc', '$') AS Wrong, CHARINDEX('$', 'a$bc') AS Ok
/*
Wrong       Ok
----------- -----------
0           2
*/