Chapter 19 – Set Operators Functions
"The man who doesn't read good books has no advantage over the man who can't read them."
- Mark Twain
Rules of Set Operators
1.Each query will have at least two SELECT Statements separated by a SET Operator
2.SET Operators are UNION, INTERSECT, or EXCEPT/MINUS
3.Must specify the same number of columns from the same domain (data type/range)
4.If using Aggregates, both SELECTs much have their own GROUP BY
5.Both SELECTS must have a FROM Clause
6.The First SELECT is used for all ALIAS, TITLE, and FORMAT Statements
7.The Second SELECT will have the ORDER BY statement which must be a number
8.When multiple operators the order of precedence is INTERSECT, UNION, and EXCEPT/MINUS
9.Parentheses can change the order ...