The EXISTS condition is an operator whose right operand is a subquery. The result of an EXISTS condition is true if the subquery resolves to at least one row. The result of a NOT EXISTS condition is ...

I’ve created a script that monitors a table in a SQL Server database. I’m only interested in one column in the table: TimeStamp. If the maximum (newest) value in TimeStamp is more than 30 minutes ...

The beauty and joy of a relational database is the concept of relational closure—everything is a table. Beyond the eponymous table, query results are also “tables.” Any query serves as a table to be ...