临时表滥用。

特别是这类事情:

SELECT personid, firstname, lastname, age
INTO #tmpPeople
FROM People
WHERE lastname like 's%'

DELETE FROM #tmpPeople
WHERE firstname = 'John'

DELETE FROM #tmpPeople
WHERE firstname = 'Jon'

DELETE FROM #tmpPeople
WHERE age > 35

UPDATE People
SET firstname = 'Fred'
WHERE personid IN (SELECT personid from #tmpPeople)

不要从查询中构建临时表，只是为了删除不需要的行。

是的，我在生产db中看到过这种形式的代码页。

没有使用With子句或适当的连接并依赖子查询。

反模式:

select 
 ...
from data
where RECORD.STATE IN (
          SELECT STATEID
            FROM STATE
           WHERE NAME IN
                    ('Published to test',
                     'Approved for public',
                     'Published to public',
                     'Archived'
                    ))

好: 我喜欢使用with子句使我的意图更易于阅读。

with valid_states as (
          SELECT STATEID
            FROM STATE
           WHERE NAME IN
                    ('Published to test',
                     'Approved for public',
                     'Published to public',
                     'Archived'
                    )
select  ... from data, valid_states
where data.state = valid_states.state

最好的:

select 
  ... 
from data join states using (state)
where 
states.state in  ('Published to test',
                     'Approved for public',
                     'Published to public',
                     'Archived'
                    )

1)我不知道这是否是一个“官方的”反模式，但我不喜欢并试图避免在数据库列中使用字符串文字作为魔法值。

MediaWiki表'image'中的一个例子:

img_media_type ENUM("UNKNOWN", "BITMAP", "DRAWING", "AUDIO", "VIDEO", 
    "MULTIMEDIA", "OFFICE", "TEXT", "EXECUTABLE", "ARCHIVE") default NULL,
img_major_mime ENUM("unknown", "application", "audio", "image", "text", 
    "video", "message", "model", "multipart") NOT NULL default "unknown",

(我只是注意到不同的大小写，另一个要避免的事情)

我设计了这样的情况，int查找表ImageMediaType和ImageMajorMime与int主键。

2)日期/字符串转换，依赖于特定的NLS设置

CONVERT(NVARCHAR, GETDATE())

没有格式标识符

我最担心的是450列的访问表，这些表是由总经理最好的朋友狗美容师的8岁儿子整理的，还有那个不可靠的查找表，它之所以存在，是因为有人不知道如何正确地规范化数据结构。

通常，这个查找表是这样的:

ID INT,
Name NVARCHAR(132),
IntValue1 INT,
IntValue2 INT,
CharValue1 NVARCHAR(255),
CharValue2 NVARCHAR(255),
Date1 DATETIME,
Date2 DATETIME

我已经记不清有多少客户的系统依赖于这种可恶的东西了。

我最不喜欢的是

Using spaces when creating tables, sprocs etc. I'm fine with CamelCase or under_scores and singular or plurals and UPPERCASE or lowercase but having to refer to a table or column [with spaces], especially if [ it is oddly spaced] (yes, I've run into this) really irritates me. Denormalized data. A table doesn't have to be perfectly normalized, but when I run into a table of employees that has information about their current evaluation score or their primary anything, it tells me that I will probably need to make a separate table at some point and then try to keep them synced. I will normalize the data first and then if I see a place where denormalization helps, I'll consider it. Overuse of either views or cursors. Views have a purpose, but when each table is wrapped in a view it's too much. I've had to use cursors a few times, but generally you can use other mechanisms for this. Access. Can a program be an anti-pattern? We have SQL Server at my work, but a number of people use access due to it's availabilty, "ease of use" and "friendliness" to non-technical users. There is too much here to go into, but if you've been in a similar environment, you know.

回复:使用@@IDENTITY代替SCOPE_IDENTITY()

两者都不能用;使用输出代替

参见https://connect.microsoft.com/SQLServer/feedback/details/328811/scope-identity-sometimes-returns-incorrect-value