I have the first edition of SharePoint 2010 (no patches) and I need to upgrade it to the 2013 version. When executing this command:
Mount-SPContentDatabase "MyDatabase" -DatabaseServer "MyServer" -WebApplication https://sitename
I faced several errors when executing SQL DDL script
due to the vast differences between the database schemas.
Please give me your suggestions if we need any prerequisite or any things.
There are some steps to migrate from sp2020 to sp2013. In the end, if you done all rignt, cmdlet Mount-SpContentDatabase correctly upgrade your content database to new schema.
But first of all you need do
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If you have errors - please, paste here text error message.