TABLESAMPLE returns a random sample of rows by percent or row count. My examples show why the same query returns a different number of rows each time.
SQL SERVER – Script/Function to Find Last Day of Month
A one line DATEADD query to find the last day of month for any date. It handles leap years: February 2008 gives the 29th and 2007 the 28th.
SQL SERVER – Math Functions Available in SQL Server
One list of the Math Functions available in SQL Server, from ABS and CEILING to SQRT and TAN, and why RAND is the only nondeterministic one among them.
SQL SERVER – Fix: Error 130: Cannot perform an aggregate function on an expression containing an aggregate or a subquery
Error 130 says you cannot perform an aggregate function on an expression containing an aggregate, like AVG(COUNT()). A derived table gets around it.
SQL SERVER – Binary Sequence Generator – Truth Table Generator
A script that builds a 512 row truth table with its decimal value and binary sequence, using CROSS JOINs on a bit table. Add or remove joins to resize it.
SQUARE: Expect a float Result From Numeric Inputs
SQUARE accepts numeric inputs convertible to float and returns float. Explicit decimal display keeps this small example readable without claiming exact decimal multiplication.
SQL SERVER – Query to Find First and Last Day of Current Month – Date Function
One query to find the First and Last Day of Current Month in SQL Server, plus the last day of the previous month and the first day of the next.