Lessons Learned #536: Error the database type is not understood by the data reader.
This week we have been working on a support case where our customer had the following message 50006: Error the database type is not understood by the data reader when exporting using SQL Server Management Studio to a bacpac. We also observed that other tools showed the same message Checking SQL Server Management Studio, we faced the following error screen: Could not export schema and data from database. (Microsoft.SqlServer.Dac) ADDITIONAL INFORMATION: 50006: Error the database type '' is not understood by the data reader. (Microsoft.Data.Tools.Schema.Sql) As part of our investigation, we validated that the native export tool SQLPackage did not produce the same error. This indicated that the issue was not directly related to the database itself, but rather to the version of SSMS (or the specific client tool being used). After further analysis, we identified the root cause: This error occurs due to a limitation in SSMS v20 (and some third-party export/backup tools). Specifically, these tools do not support the JSON data type in SQL database columns. As a result, any attempt to export or back up a database containing JSON columns with these versions will fail. After the analysis, we've found to be a limitation in the SSMS v.20 and other third-party backup/export tool, which does not support the JSON data type in SQL database columns. As a result, any attempt to export or back up a database containing JSON columns using this tool would fail. In our case, the issue was resolved after the customer upgraded to SSMS v21, which includes support for JSON data types during bacpac exports. Afterthe upgrade, the export process worked as expected.
