Error "Violation of PRIMARY KEY constraint 'PK_Name'. Cannot insert duplicate key in object 'dbo.Table'" when applying snapshot to the Subscriber database

When setting up merge replication, you may get the following error:

Violation of PRIMARY KEY constraint 'PK_Name'. Cannot insert duplicate key in object 'dbo.Table'

while the initial snapshot is applied to the Subscriber database.

How can data that violates no primary key constraints at the Publisher cause such an error at the Subscriber? This can be caused by different collations used by the Publisher and Subscriber (at the database, table or column level).

If the Publisher database has a case-sensitive collation (e.g. SQL_Latin1_General_CP1_CS_AS ), the following data is correct (columns Type and Code are a primary key):

Type  Code  Column1
024   N     ...
024   n     ...
024   g     ...

However, an attempt to insert these rows into a table with case-insensitive collation (e.g. Latin1_General_CI_AI) will cause a primary key violation.