In SQL Server, the GROUPING() function is used to distinguish the null values that are returned by ROLLUP, CUBE, or GROUPING SETS from standard null values.
Basically it tells us whether a specified column expression in a GROUP BY list is aggregated or not.
The GROUPING() function returns either 1 or 0 (1 indicates that the column expression is aggregated and 0 indicates that it’s not).
The SQL DISTINCT clause allows us to remove redundant duplicate rows from our query results. For example if two rows contain the same values, then only one of them is returned.
But how does DISTINCT handle NULL values?
Let’s find out.
Continue readingSQL Server has a CHECKSUM_AGG() function that allows us to get the checksum of the values in a group. This can be useful for detecting changes in the values in a column.
In SQL Server, the APPROX_PERCENTILE_DISC() function calculates and returns an approximate percentile based on a discrete distribution of the column values.
We pass the desired percentile to the function when we call it.
Continue readingIf you’re getting an error message that reads “The function ‘PERCENT_RANK’ must have an OVER clause with ORDER BY” in SQL Server, it’s probably because you’ve omitted the ORDER BY clause from the OVER clause when using the PERCENT_RANK() function.
The PERCENT_RANK() function requires an OVER clause that contains an ORDER BY clause. This error happens when we include the OVER clause but not the ORDER BY clause.
To fix this error, add an ORDER BY clause to the OVER clause.
In SQL Server, the APPROX_PERCENTILE_CONT() function calculates and returns an approximate percentile based on a continuous distribution of the column value. This is an interpolated value from the set of values in a group based on percentile value and sort specification.
Like most other RDBMSs, SQL Server has an AVG() function that returns the average of the values in a group.
Below are examples that demonstrate how the AVG() function works in SQL Server.
If you’re getting an error in SQL Server that reads “The least function requires 1 to 254 arguments“, it’s probably because you’re either passing too few or too many arguments to the LEAST() function.
As the error message states, the LEAST() function requires at least 1 argument, and no more than 254 arguments.
To fix this issue, be sure to pass at least 1 argument, and no more than 254 arguments when using the LEAST() function.
In statistics, the mode is the most commonly occurring value in a data set. When using SQL databases, we can easily run a SQL query to find out the mode of a given column.
Below are several options we can use to calculate the mode in SQL.
Continue readingSuppose you’re trying to query column, but you need to set a minimum value to be returned, even if the column contains values that are less than that minimum. For example, you want a minimum value of 50 to be returned, even if the column contains values that are less than 50.
We can use the GREATEST() function to build such a query.