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I am updating remote MySQL database by comparing row by row from local MSSQL one. Idea was to do update in 3 steps:

1: select all ID's from local and execute following query on remote:

delete from REMOTE_DATABASE.TABLE where ID not in 
( list of LOCAL_DATABASE.TABLE ID's linked by OR condition )

2: select ID's from LOCAL_DATABASE.TABLE that are not exist on remote and insert

3: update rows that have both tables.

My question is regarding first step: I have 50000+ products. I am working in C# and I could join all ID's in string but I was wondering can query with 50000 ID's linked by OR condition be executed? Is it a wrong approach?

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1 回答 1

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所以我以前做过这个。很久以前，所以我可能会错过一步，但我希望你能明白。

  1. 在 MSSQL 数据库上设置链接服务器到 MySQL 数据库。请参阅此链接的 MySQL 服务器文章

  2. SELECT你想要的所有表从链接服务器到 MSSQL SQL 上的临时表。但是SELECT * INTO #temp FROM linkedserver.tablename，最好创建一个适当的临时表并索引您将要加入的列，即

    CREATE TABLE #Test
(
ID INT PRIMARY KEY NOT NULL
)
INSERT INTO #Test
SELECT * FROM linkedserver.tablename

  3. Do a LEFT/RIGHT JOIN to find new ID on the local machine and insert them into the remote server via linked server. See this link for more information on how to use LEFT/RIGHT joins to get the new records when comparing two tables Using Left join to find new rows

  4. Update the remote server with a UPDATE statement and JOIN in it. So basically using a INNER JOIN do a update to the remote server with the values in the temp table.

Now there might be some errors you run into with the syntax post them here and I can try and resolve them for you. However I have used this technique to synchronize between MySQL and MSSQL servers and it works pretty well. As it is SETS based and not RBAR based it is very fast as well.

于 2013-08-16T04:15:51.067 回答