Question

有人可以告诉我为什么抱怨这个？我正在使用SQL Server，其中一个名为test的表和一个名为word

的列

这是我的疑问：

SELECT TOP 1
COUNT(*) AS count, 
(LEN(word) - LEN(REPLACE(word,'A',''))) AS letters
FROM dbo.TEST 
WHERE 
word LIKE '******' 
GROUP BY letters 
ORDER BY count DESC

这是结果错误：

Msg 207, Level 16, State 1, Line 7
Invalid column name 'letters'.

为什么要抱怨我的别名？

Answer 1

您不能在GROUP BY中使用别名，请使用相同的计算列：

SELECT TOP 1
COUNT(*) AS count, 
(LEN(word) - LEN(REPLACE(word,'A',''))) AS letters
FROM dbo.TEST 
WHERE 
word LIKE '******' 
GROUP BY (LEN(word) - LEN(REPLACE(word,'A','')))
ORDER BY count DESC

Answer 2

您不能在GROUP BY子句中使用别名。这是由于SQL处理顺序，GROUP BY在SELECT之前处理。尝试更换：

GROUP BY letters

与

GROUP BY (LEN(word) - LEN(REPLACE(word,'A','')))

Answer 3

您无法在查询中使用别名。你需要的是：

SELECT TOP 1
COUNT(*) AS count, 
(LEN(word) - LEN(REPLACE(word,'A',''))) AS letters
FROM dbo.TEST 
WHERE 
word LIKE '******' 
GROUP BY (LEN(word) - LEN(REPLACE(word,'A','')))
ORDER BY count DESC

希望有所帮助

Answer 4

在查询中更改分组

   SELECT TOP 1
            COUNT(*) AS count ,
            ( LEN(word) - LEN(REPLACE(word, 'A', '')) ) AS letters
    FROM    dbo.TEST
    WHERE   word LIKE '******'
    GROUP BY ( LEN(word) - LEN(REPLACE(word, 'A', '')) )
    ORDER BY count DESC

SQL查询和别名的问题

4 个答案: