You might encounter the error “Conversion failed when converting from a character string to uniqueidemtifier” while working in an SQL server. This error is because you are trying to convert a string value to uniqueidemtifier in SQL but the conversation fails because a string is not a valid uniqueidemtifier.
Resolve Conversion issue:
To resolve this error please follow these steps
Verify your Input Value: Check the string you’re trying to convert and make sure it is compatible with uniqueidentifier. In SQL Server, a uniqueidentifier is a 36-character string that consists of alphanumeric characters separated by hyphens (e.g., “6G9619GG-8B86-D011-C42D-00C04FC864FF”). Make sure your input string matches this format and only contains alphanumeric characters.
Implement TRY_CAST or TRY_CONVERT: you can use the TRY_CAST or TRY_CONVERT function instead of CAST or CONVERT. The TRY_CAST/TRY_CONVERT function attempts the conversion and returns NULL if it fails, rather than throwing an error. You can then handle the NULL value as needed in your query.
SELECT TRY_CAST('InvalidValue' AS uniqueidentifier) AS NewValue;
The above query returns null instead of throwing an error if the conversion fails.
Validate your Input: Try to validate your input in your application before using it as input. Make sure the input only contains alphanumeric characters and does not contain any invalid characters.
If you follow the above steps you should be able to resolve the error “”Conversion failed when converting from a character string to uniqueidemtifier” in your application and handle conversion correctly.