Page 173 - SQL

DB2

SELECT * FROM TableName WITH UR;

where UR stands for "uncommitted read".

If used on table that has record modifications going on might have unpredictable results.

Select distinct (unique values only)

SELECT DISTINCT ContinentCode
FROM Countries;

This query will return all DISTINCT (unique, different) values from ContinentCode column from
Countries table

ContinentCode

OC

EU

AS

NA

AF

SQLFiddle Demo

Select with condition of multiple values from column

SELECT * FROM Cars WHERE status IN ( 'Waiting', 'Working' )

This is semantically equivalent to

SELECT * FROM Cars WHERE ( status = 'Waiting' OR status = 'Working' )

i.e. value IN ( <value list> ) is a shorthand for disjunction (logical OR).

Get aggregated result for row groups

Counting rows based on a specific column value:

SELECT category, COUNT(*) AS item_count
FROM item
GROUP BY category;

https://riptutorial.com/ 155