An update label is one clue, the build number is the identity. I show how to read both, compare builds safely, and avoid the NULL typo trap.
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SQLAuthority News – Presented at Bangalore DevCon August 4, 2012
Notes from Bangalore DevCon 2012: two tracks, 12 sessions and more than 140 attendees, plus my own session on SQL tips and tricks for web developers.
SQL SERVER – Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – T-SQL Example – Part 2 of 2
Part 2 of the disappearing rows story: a T-SQL example showing how ON UPDATE CASCADE and ON DELETE CASCADE made my friend’s rows vanish, no virus involved.
SQL SERVER – Curious Case of Disappearing Rows – ON UPDATE CASCADE and ON DELETE CASCADE – Part 1 of 2
Rows kept vanishing from a product table with no DELETE anywhere in the code. Part 1 of a puzzle that leads to ON UPDATE CASCADE and ON DELETE CASCADE.
Measuring Time Between Workflow Steps With LEAD
Status rows hold timestamps, not durations. I use LEAD to measure each step, keep unfinished steps NULL, and show why zero ruins your averages.
What Is a Primary Key, and What Happens Without One?
A primary key is the promise that every row can be told apart. Why NULL is refused, what a table without one actually costs you, how it differs from a unique constraint, and when to choose a natural key over a made up one.
CHECK Constraints and NULL: Why Unknown Passes the Test
Why does a CHECK (Quantity > 0) happily store a row with no quantity? Three-valued logic, a small demo, and the NOT NULL fix.