String and dates
Search for a string across columns
DROP TABLE bedroom
CREATE TABLE bedroom(
name VARCHAR(20),
floorcolor VARCHAR (20),
ceilingcolor VRACHAR(20),
wallcolor VARCHAR(20));
INSERT INTO bedroom VALUES ('Jim','RED','GREEN','YELLOW');
INSERT INTO bedroom VALUES ('Bob','YELLOW','BLUE','BLACK');
INSERT INTO bedroom VALUES ('Allan','BLUE','PINK','BLACK');
INSERT INTO bedroom VALUES ('George','BLUE','GREEN','OAK');
SELECT name FROM bedroom WHERE floorcolor = 'YELLOW' OR ceilingcolor = 'YELLOW' OR wallcolor = 'YELLOW'
Using OR increases the chances for careless mistakes instead CONCAT could be used to make the query more efficient. To avoid problems make sure to add in separators and if a value cna be null make sure to use it is wrapped in COALESCE OR NVL for example: COALESCE(floorcolor,).
SELECT name FROM bedroom
WHERE CONCAT (':',floorcolor,':',ceilingcolor,':',wallcolor,':')
LIKE '%:YELLOW:%'
Hack 10 Converting subqueries into joins
Hack 11 Converting aggregate subqueries into joins
Hack 16 Search for a String across columns
Hack 24 Multiply Across a Result Set
Hack 25.5 Splitting and combining columns
Hack 26 Include the rows your JOIN forgot
Hack 30 Calculate the maximum/minimum of two fields
Hack 33 Get values and subtotals in one shot
Hack 50 Combine tables containing different data
Hack 51/52 Display rows as columns
Hack 55 Import Someone Else's Data
Hack 62 Issue Queries Without Using a Table
Hack 63 Generate rows without tables
Hack 72 Extract a subset of the results
Hack 78 Break it down by Range
Hack 88 Test two values from a subquery