Query over two databases has error due to collation mismatch

问题

I'm an IT consultant that usually manages hardware and networks but our programmers are on leave at the moment. I've made some modifications to a MSSQL query that runs over two databases on each of our 15 site's Practice Management Software servers and I'm getting an error on a few of the servers relating to a collation conflict.

On most of our site's servers it runs fine, but there is 4 out the 15 servers that appear two have the databases using different collation for some reason.

I've looked into trying to change the collation, but it didn't go well, so I was hoping maybe I could tweak the query so the difference in collation didn't matter for these servers. In fact, it'd be better if the query was 'collation agnostic' so that I could use the same query across all servers without a care for the collation... Can this be done?

The exact error is

Msg 446, Level 16, State 11, Line 1 Cannot resolve collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in CASE operator for DISTINCT operation.

Msg 446, Level 16, State 11, Line 1 Cannot resolve collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in CASE operator for DISTINCT operation.

And the query I'm running is:

SELECT DISTINCT
-- setup columns
[cases].[reference] as MatterNumber,
[dd_entity_d2].[type] as ClientType,
[dd_client].[clientname] as MatterName,
CASE WHEN [dd_entity_d2].[type] ='Individual' THEN etClient.FirstName ELSE [dd_entity_d4].[firstname] END AS FirstName,
CASE WHEN [dd_entity_d2].[type] ='Individual' THEN etClient.LastName   ELSE [dd_entity_d4].[lastname] END AS LastName,
CASE WHEN [dd_entity_d2].[type] ='Individual' THEN [dd_entity_d2].[email]   ELSE [dd_entity_d4].[email] END AS Email,
etActing.[PreferredName] ActingPerson,
[cases].[category] as MatterType,
mt.CreatedOn as MatterOpened,
case mt.[Status]
    when 0 then 'In Progress'
    When 1 then 'On Hold'
    when 2 then 'Completed'
    when 3 then 'Not Proceeding'
else 'Unknown' end as MatterStatus
-- mt.LastUpdatedOn as LastModified,
-- end columns
-- setup data
FROM PracticeEvolve_doc.dbo.[cases]
INNER JOIN PracticeEvolve_c1.dbo.DocumaticsMap dm on dm.DocumaticsID = [cases].ID and dm.Entitytype = 'Matter'
INNER JOIN PracticeEvolve_c1.dbo.[Matter] mt on mt.Matterid = dm.ClickOneID
INNER JOIN PracticeEvolve_c1.dbo.[Client] cl on mt.ClientID = cl.ClientID
INNER JOIN PracticeEvolve_c1.dbo.[Entity] etClient on cl.EntityID = etClient.EntityID
LEFT JOIN PracticeEvolve_c1.dbo.EmployeeMatter emActing on emActing.MatterID = mt.MatterID and emActing.AssociationTypeID = 15
LEFT JOIN PracticeEvolve_c1.dbo.Employee eActing on eActing.EmployeeID = emActing.EmployeeID
LEFT JOIN PracticeEvolve_c1.dbo.Entity etActing on etActing.EntityID = eActing.EntityID
LEFT JOIN PracticeEvolve_doc.dbo.[dd_client] ON [dd_client].[id]=[cases].[clientid]
LEFT JOIN PracticeEvolve_doc.dbo.[dd_manytomany] AS [dd_manytomanydd_entity_d2] ON [dd_manytomanydd_entity_d2].[fkid] = [dd_client].[fk_entities]
LEFT JOIN PracticeEvolve_doc.dbo.[dd_entity] as [dd_entity_d2] ON [dd_entity_d2].[id] = [dd_manytomanydd_entity_d2].[pkid]
LEFT JOIN PracticeEvolve_doc.dbo.[dd_manytomany] AS [dd_manytomanydd_party_d3] ON [dd_manytomanydd_party_d3].[fkid] = [dd_entity_d2].[fk_parties]
LEFT JOIN PracticeEvolve_doc.dbo.[dd_party] as [dd_party_d3] ON [dd_party_d3].[id] = [dd_manytomanydd_party_d3].[pkid]
LEFT JOIN PracticeEvolve_doc.dbo.[dd_manytomany] AS [dd_manytomanydd_entity_d4] ON [dd_manytomanydd_entity_d4].[fkid] = [dd_party_d3].[fk_entity]
LEFT JOIN PracticeEvolve_doc.dbo.[dd_entity] as [dd_entity_d4] ON [dd_entity_d4].[id] = [dd_manytomanydd_entity_d4].[pkid]
-- end data
-- setup filters
WHERE [cases].[deleted]=0   
    -- AND DATEPART(m, mt.CreatedOn) = DATEPART(m, DATEADD(m, -1, getdate()))
    -- AND DATEPART(yyyy, mt.CreatedOn) = DATEPART(yyyy, DATEADD(m, -1, getdate())) 
    AND mt.CreatedOn >= '2015-07-01'   
    -- AND [dd_entity_d2].[type] = 'Individual'
    -- AND mt.LastUpdatedOn >= '2017-04-02'   
    -- AND mt.[status] = 0
-- end filters 
-- setup sort
ORDER BY Email ASC
-- end sort and query

PracticeEvolve_c1 is SQL_Latin1_General_CP1_CI_AS and PracticeEvolve_doc is Latin1_General_CI_AS.

I'm out of my depth here and would greatly appreciate any help you may be able to offer.

Cheers - Reece

EDIT: FWIW - this is the error I got when I tried to change the database collation:

The object 'MonthToDays365' is dependent on database collation. The database collation cannot be changed if a schema-bound object depends on it. Remove the dependencies on the database collation and then retry the operation

回答1:

Just amend the CASE expression and include the COLLATE command

CASE WHEN [dd_entity_d2].[type] COLLATE SQL_Latin1_General_CP1_CI_AS 
          ='Individual' 
THEN etClient.FirstName COLLATE SQL_Latin1_General_CP1_CI_AS 
ELSE [dd_entity_d4].[firstname] COLLATE SQL_Latin1_General_CP1_CI_AS 
END AS FirstName,

来源：https://stackoverflow.com/questions/48186025/query-over-two-databases-has-error-due-to-collation-mismatch

标签

sql

sql-server

database

collation