blocks|key|4710621|text|这是因为'full_name‘是文字而不是列名，因此在WHERE子句级别上不存在|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4710622|您需要添加|4710623|OR+f_name+%2B+'+'+%2B+l_name+=+user-input|code-block|syntax|javascript|4710624|instead+of+'full_name‘=用户输入|4710625|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

that is because 'full_name' is a literal and not a column name, it does not exists at the WHERE clause level

you need to add

<pre><code>OR f_name + ' ' + l_name = user-input
</code></pre>

instead of 
OR 'full_name' = user-input

blocks|key|3867706|text|根据“授人以鱼”的理论...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3867707|不能在where或group+by子句中使用列别名。您可以在order+by子句中使用它。要以您想要的方式使用列别名，您必须执行如下操作：|3867708|SELECT+[Full+Name]+FROM
++(SELECT+f_name,+l_name,+f_name+%2B+'+'+%2B+l_name+AS+[Full+Name]
+++FROM+users_table)
++WHERE+[Full_Name]+=+@paramVal|code-block|syntax|javascript|3867709|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Under the "teach a man to fish" theory ...

You cannot use a column alias in a where or group by clause. You can use it in an order by clause. To use a column alias the way you want to, you would have to do something like ...

<pre><code>SELECT [Full Name] FROM
 (SELECT f_name, l_name, f_name + ' ' + l_name AS [Full Name]
 FROM users_table)
 WHERE [Full_Name] = @paramVal
</code></pre>

blocks|key|1189973|text|“full_name”是文字字符串，而不是列...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1189974|(f_name+%2B‘’%2B+l_name)+=用户输入|1189975|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

'full_name' is a literal string not the column...

(f_name + ' ' + l_name) = user-input

blocks|key|647492|text|尝试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|647493|SELECT+f_name,+
+++++++l_name,+
+++++++(f_name+%2B+'+'+%2B+l_name)+AS+full_name
FROM+users_table
WHERE+f_name+=+user-input
+++OR+l_name+=+user-input
+++OR+f_name+%2B+'+'+%2B+l_name+=+user-input|code-block|syntax|javascript|647494|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

try:

<pre><code>SELECT f_name, 
 l_name, 
 (f_name + ' ' + l_name) AS full_name
FROM users_table
WHERE f_name = user-input
 OR l_name = user-input
 OR f_name + ' ' + l_name = user-input
</code></pre>

blocks|key|1190040|text|这将会起作用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1190041|SELECT+*
FROM+users_table
WHERE+CONCAT(first_name,'+',last_name)+=+user-input;|code-block|syntax|javascript|1190042|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This will work:

<pre><code>SELECT *
FROM users_table
WHERE CONCAT(first_name,' ',last_name) = user-input;
</code></pre>

blocks|key|1182729|text|对于初学者，删除最后一个where条件中full_name两边的单引号。现在，将用户输入与字符串文字'full_name‘进行比较。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1182730|连接部分应该是a-ok！|1182731|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

For starters, remove the single quotes from around the full_name in the last where criteria. Now the user-input is compared to the string literal 'full_name'.

The concatenation part should be a-ok!

blocks|key|4710734|text|问题出在下面这一行：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4710735|OR+'full_name'+=+user-input|code-block|syntax|javascript|4710736|假设这确实是您所写下的内容，则将文字字符串"full_name“与所提供的输入进行比较。用单引号将某物引起来，将其视为字面量。尝试以下操作：|4710737|SELECT+f_name,+l_name,+(f_name+%2B+'+'+%2B+l_name)+AS+full_name
FROM+users_table
+++WHERE+f_name+=+user-input
+++OR+l_name+=+user-input
+++OR+full_name+=+user-input|4710738|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

The problem is in this line:

<pre><code>OR 'full_name' = user-input
</code></pre>

Provided that's actually what you have written down, you are comparing the literal string "full_name" to the provided input. Putting single quotes around something treats it as a literal. Try the following:

<pre><code>SELECT f_name, l_name, (f_name + ' ' + l_name) AS full_name
FROM users_table
 WHERE f_name = user-input
 OR l_name = user-input
 OR full_name = user-input
</code></pre>

blocks|key|1190070|text|确保用户输入"full_name“(不带引号)作为用户输入，数据库将返回一些行。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1190071|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Make sure that the user enters "full_name" (without the quotes) as the user-input and the database will return some rows.

I have a query that takes input from the end user and compares it to 2 columns individually, and the two columns concatenated.

<pre><code>SELECT f_name, l_name, (f_name + ' ' + l_name) AS full_name
FROM users_table
WHERE f_name = user-input
 OR l_name = user-input
 OR 'full_name' = user-input
</code></pre>

Excuse the massive syntax fail, but I assure you it's correct in the program.

It is written in PHP, querying a SQL SERVER 2005 database, and is case insensitive.

Typing one name (first or last) will return correct results, but typing first, then space, then last, returns an empty set.

Any ideas?

SQL concatenating strings?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有一个从最终用户获取输入的查询，并将其分别与2列进行比较，并将这两列连接在一起。SELECT f_name, l_name, (f_name + ' ' + l_name) AS full_nameFROM users_tableWHERE f_name = user-input   OR l_name = user-input   OR 'full_name' = user-input抱歉，大

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