sql-server - varchar 值隐式转换为 varchar - 排序规则冲突

Question

运行此脚本时出现以下错误。我尝试过使用以下内容:整理 Latin1_General_CI_AS。请问可以排序吗？谢谢

Msg 457, Level 16, State 1, Line 8
Implicit conversion of varchar value to varchar cannot be performed because the collation of the value is unresolved due to a collation conflict

DECLARE @AccountID INT 
SET @AccountID = 12

SELECT TOP 1    ac.AccountID,
            co.Email,
            ao.AccountOptionID
FROM CRM.acc.Account ac
INNER JOIN CRM.[profile].[Profile] pr
    ON pr.ProfileID = ac.ProfileFK
INNER JOIN CRM.[profile].Contact co
    ON pr.ProfileID = co.ProfileFK
LEFT JOIN CRM.acc.[AccountOption] ao
    ON ao.AccountFK = ac.AccountID
LEFT JOIN (
            SELECT OptionID
            FROM CRM.acc.[Option]
            WHERE [Name] = 'SMS messages') op
    ON op.OptionID = ao.OptionFK
WHERE ac.AccountID = @AccountID

UNION ALL

SELECT      u.UnsubscribeID,
        u.EmailAddress,
        u.SentEmailFK
FROM  Email.dbo.Unsubscribe u
  INNER JOIN  (
                    SELECT      CASE
                                      WHEN AccountTypeFK = 2 THEN OnlineBillingEmail
                                      ELSE EmailBillingEmail
                                END [EmailAddress]
                    FROM  CRM.acc.Account
                    WHERE AccountID = @AccountID                    
                    ) ace
        ON ace.EmailAddress COLLATE DATABASE_DEFAULT  = u.EmailAddress COLLATE DATABASE_DEFAULT
WHERE ISNULL(ace.EmailAddress, '') != ''

Answer 1

您的数据库似乎有不同的排序规则类型。然后，在连接表或连接到其他数据库中的表时可能会遇到问题，如本例所示。为了解决这个问题，您可以指定列的排序规则，或者在连接两列时使用 COLLATE 子句强制进行排序规则。检查more info about collation in MSDN

您还需要指定使用有问题列的 COLLATE 子句。 Check this answer ，它回答了一个非常相似的问题

最好在全局范围内坚持使用单一排序规则。否则你会遇到问题。

查看different collation styles的详细解释

已编辑:要检查列排序规则，请使用此代码段

SELECT name, collation_name
  FROM sys.columns
  WHERE OBJECT_ID IN (SELECT OBJECT_ID
                        FROM sys.objects
                       WHERE type = 'U'
                         AND name = 'your_table_name'
                      )
    AND name = 'your_column_name'

编辑:添加片段以获取数据库上具有不同排序规则的所有列

SELECT [TABLE_NAME] = OBJECT_NAME([id]),
       [COLUMN_NAME] = [name],
       [COLLATION_NAME] = collation
  FROM syscolumns
 WHERE collation <> 'your_database_collation_type'
   AND collation IS NOT NULL
   AND OBJECTPROPERTY([id], N'IsUserTable')=1