SQL Server

ISNUMERIC()? No, thank you!

2. 6. 2014

Can we trust ISNUMERIC() function when checking if it is safe cast string value to numeric data type? Definitely not, because it´s more or less unusable for this purpose, because we can´t be sure what is hidden in string to be converted. And trust me: there is lot of surprises…

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SQL Server

Change in Query Plan Can Affect Query Result Set (Table Spool)

10. 5. 2014
It´s legitimate expectation that a SELECT statement will return consistent results independently on number of rows returned or an internal implementation of query processing. But it is not always true. I will demonstrate it on a simple query using NEWID() function. This function should return new value on every call…
SQL Server

How to prevent views with outdated metadata?

23. 8. 2013
SQL Server is persisting various metadata when a new view is created in SQL Server. When underlying objects are changed later then view metadata aren’t updated automatically and this outdated metadata can cause several issues later. Let’s see one simple example. We will create a dbo.SampleTable table and create view…