Fix Msg 529 “Explicit conversion from data type int to xml is not allowed” in SQL Server

If you’re getting SQL Server error Msg 529 that reads something like Explicit conversion from data type int to xml is not allowed, it’s probably because you’re trying to perform a data type conversion that’s not permitted.

SQL Server doesn’t allow certain conversions. If you try to perform such a conversion, you’ll get this error.

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How to Check a Column’s Data Type in SQL

In SQL, the columns information schema view, which returns information about columns, is an ISO standard view that is supported by most of the major RDBMSs. You can use this view to get information about a column’s data type.

Most of the major RDBMs also provide other methods for getting column information.

Here are examples of getting the data type of a column in various SQL databases.

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Fix Msg 8117 “Operand data type varchar is invalid for sum operator” in SQL Server

If you’re getting SQL Server error Msg 8117 with the message Operand data type varchar is invalid for sum operator, it’s because you’re passing the wrong data type to an operator or function.

In this case, the error indicates that we’re passing a string to the SUM() function. The SUM() function does not operate on strings. It only works on numeric types.

The same error (Msg 8117) can also occur in other contexts – it’s not limited to the SUM() function.

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How to Detect if a Value Contains at Least One Number in SQL Server

Sometimes you might need to search a database table for only those rows that contain at least one number in a given column.

Strictly speaking, numbers can be represented by words and other symbols, but for the purpose of this article, “number” means “numerical digit”.

Below is an example of how to use T-SQL to find rows that contain at least one number in SQL Server.

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