Understanding the STDDEV_SAMP() Function in MySQL

In MySQL, the STDDEV_SAMP() function returns the sample standard deviation of a given expression. This is the square root of VAR_SAMP().

STDDEV_SAMP() is an aggregate function, and so it can be used with the GROUP BY clause.

If there are no matching rows, or if the expression is NULL, STDDEV_SAMP() returns NULL.

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Fix Error Msg 6855 “Inline schema is not supported with FOR XML PATH” in SQL Server

If you’re getting error Msg 6855 in SQL Server that reads “Inline schema is not supported with FOR XML PATH“, it’s because you’re trying to add an inline schema to an XML document that you’re generating using PATH mode with the FOR XML clause.

As the message alludes to, PATH mode doesn’t support the ability to create an inline schema when using the FOR XML clause.

To fix this issue, either use a different mode to generate the XML with an inline schema (specifically, use either AUTO or RAW mode), or don’t generate an inline schema at all.

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Fix “Explicit conversion from data type int to date 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 date is not allowed, it’s because you’re trying to perform an explicit 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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