In SQL Server, FIRST_VALUE() is a window function that returns the first value in an ordered set of values.
Basically, we can use it to get a value from the first row of a query result set or partition. This can be handy if we want to compare a value in the current row with a value in the first row, or use it as part of a calculation.
Continue readingIn SQL Server, PERCENT_RANK() is a window function that calculates and returns the relative rank of a row within a group of rows, expressed as a value between 0 and 1.
In other words, it returns the percentage of partition values less than the value in the current row, excluding the highest value.
Continue readingIn SQL Server, the CUME_DIST() function calculates and returns the cumulative distribution of a value within a group of values. This is the relative position of a specified value in a group of values.
If you’re getting error msg 6358 which reads something like 300 is not a valid style number when converting to XML, it’s probably because you’re trying to convert a value to XML, but the style that you’re specifying isn’t supported for conversions to that data type.
It’s not that the conversion can’t happen, it’s just that it can’t happen using the style that you’re specifying.
Continue readingIf 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.
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.
Continue readingIn SQL Server, we can use the sp_sequence_get_range stored procedure to generate a range of sequence numbers from a sequence object.
One common use case for sequences in SQL Server is to use them to number the results of a query. For example, we can add a column that has a number that increments with each row, similar to a row counter (but with a sequence that we define).
Continue readingIf you’re getting error msg 220 that reads something like Arithmetic overflow error for data type…, it’s probably because you’re trying to convert a value to a data type that can’t handle that value. For example, trying to convert a number to a smallint but the number’s too big to fit into a smallint.
To fix this issue, make sure you convert the value to a data type that can handle the size of the number that you’re trying to convert.
Continue readingIf you’re using FOR XML in SQL Server to output your query results as XML, you might find yourself in the situation where the XML returned has no root element. Fortunately adding a root element is easy, as I’ll show you in this article.