如何按起始字符范围进行选择？

发布于 2024-11-24 07:31:08 字数 281 浏览 2 评论 0原文

这是我的 mySQL 查询：

SELECT *
FROM `eodList` 
WHERE datechanged>='$curdate' 
GROUP BY symbolName 
ORDER BY dateChanged DESC

如何获取 symbolName 以字母 AF 开头的所有行（例如）？

更新：

我需要一些可以轻松更改为另一个范围而无需进行大量代码更改的东西。

原文

Here is my mySQL query:

SELECT *
FROM `eodList` 
WHERE datechanged>='$curdate' 
GROUP BY symbolName 
ORDER BY dateChanged DESC

How do I get all rows (for example) where symbolName starts with letters A-F?

Update:

I need something that can be easily changed to another range without alot of code changes.

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眼泪也成诗 2024-12-01 07:31:08

比正则表达式和SUBSTRING()函数调用更快。这将使用 symbolName 的索引：

WHERE symbolName >= 'A' 
  AND symbolName < 'G'

但是存在区分大小写的问题。您是否也想要以 a..f 开头的名称？

如果您只需要以大写字母开头的名称并且表具有 utf8 字符集，请使用：

WHERE symbolName >= 'A' COLLATE utf8_bin
  AND symbolName < 'G' COLLATE utf8_bin

对于其他字符集，请使用相应的 _bin 排序规则。

Faster than Regular expressions and SUBSTRING() function calls. This will use the index of symbolName :

WHERE symbolName >= 'A' 
  AND symbolName < 'G'

There is an issue with the case sensitivity though. Do you want names which start with a..f too or not?

If you want only names that start with uppercase and the table has utf8 character set, use:

WHERE symbolName >= 'A' COLLATE utf8_bin
  AND symbolName < 'G' COLLATE utf8_bin

For other character sets, use the corresponding _bin collation.

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￡噩梦荏苒 2024-12-01 07:31:08

尝试使用正则表达式

WHERE symbolName REGEXP '^[A-F]'

Try with Regex

WHERE symbolName REGEXP '^[A-F]'

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方圜几里 2024-12-01 07:31:08

SELECT *
FROM `eodList` 
WHERE datechanged>='$curdate' AND


((SUBSTRING(symbolName, 1, 1) >= "A" AND SUBSTRING(symbolName, 1, 1) <="F"))
GROUP BY symbolName 
ORDER BY dateChanged DESC

SELECT *
FROM `eodList` 
WHERE datechanged>='$curdate' AND


((SUBSTRING(symbolName, 1, 1) >= "A" AND SUBSTRING(symbolName, 1, 1) <="F"))
GROUP BY symbolName 
ORDER BY dateChanged DESC

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