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SQL Group By Top ʵÏÖ

DECLARE @temp TABLE(
id INT,
[name] VARCHAR(50),
class VARCHAR(50)
)
INSERT INTO @temp
SELECT 1,'a','A'
UNION ALL SELECT 2,'b','C'
UNION ALL SELECT 3,'c','B'
UNION ALL SELECT 4,'d','C'
UNION ALL SELECT 5,'e','B'
UNION ALL SELECT 6,'f','A'
SELECT * from @temp AS _temp WHERE [name] IN
( ......

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SQL SERVER£ºselect ×Ö·û´®Æ´½ÓÎÊÌâ

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select UserID,LastName,FirstName,UserName from SYSUser
UserID LastName FirstName UserName
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1      A        B        C
2  &nb ......

db2 V8µÄÓйØSQL limits

The following tables describe certain SQL
limits. Adhering to the most restrictive case can help the programmer
design application programs that are easily portable.
Table 7. Identifier Length Limits
Description
Limit in Bytes
Longest authorization
name (can only be single-byte characters) ......
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