DateTime Trick

GETDATE

File Groups

Causation, Correlation and Crackpots

Joe Celko explores the dangers of muddling correlation and causation, emphasises the importance of determining how likely it is that a correlation has occurred by chance, and gets stuck into calculating correlation coefficients in SQL. Along the way, Joe illustrates the consequences of leaping to the wrong conclusion from correlations with tales of Pop Dread.

Varchar or Char?

AND & OR

Concatenating Rows

Often in database design we store different values in rows to take advantage of a normalized design. However many times we need to combine multiple rows of data into one row for a report of some sort. New author Carl P. Anderson brings us some interesting T-SQL code to accomplish this.

SQL and the JOIN Operator

How the JOIN operator works, the different types of JOINs and relevant information about joining tables.

Retrieve consecutive records from the table based the value difference

Retrieve consecutive records from the table based the value difference

IN Operator