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How do I find out the differences in data between the two tables that have exact schema, and how to produce synchronisation SQL to get the union results (without duplicates) ?

These are the 2 tables:

SOURCE01.dbo.Customers (31,022 rows)

TARGET01.dbo.Customers (29,300 rows)

The schema of each table is :

  • [CustomerId] : nvarchar(255)
  • [CustomerSerializedProfile]: nvarchar(max)
  • [CreatedDatetime] : DateTime
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3 Answers 3

Using Native tools :

tablediff : the tablediff utility compares the data in the source table to the table in the destination table.

powershell : compare-object allows you to achieve that. here is a good example

third party:

redgate schema and data compare. You can even use powershell and schema/data compare to automate things.

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I've used this one recently for a similar purpose:

from SOURCE01.dbo.Customers as s
full outer join TARGET01.dbo.Customers as t
    on s.CustomerId = t.CustomerId
where s.CustomerSerializedProfile <> t.CustomerSerializedProfile
or s.CreatedDatetime <> t.CreatedDatetime
or s.CustomerId is NULL
or t.CustomerId is NULL;

(Code edited post comment; apologies, I was wining it without an instance to hand.)

It does rely on the primary key being consistent. But you have to have something consistent after all. A meta script to generate code like the above is relatively easy to write and makes many-column tables easy to compare.

As for synchronisation you will have to source left join target and 'target left join source`, then decide what you want to do with the result of each.

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This should give you the differences between the two tables, you can then wrap this in an insert query to put the differences from A into B or vice versa.

SELECT A.CustomerId, A.CustomerSerializedProfile, A.CreatedDatetime
  FROM SOURCE01.dbo.Customers A
                 FROM TARGET01.dbo.Customers
                WHERE B.CustomerId= A.CustomerId
                  AND B.CustomerSerializedProfile= A.CustomerSerializedProfile
                  AND B.CreatedDatetime= A.CreatedDatetime)
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