Difference between revisions of "Maximum"
| Line 12: | Line 12: | ||
</source> | </source> | ||
<div> | <div> | ||
| − | <p>The function for using MAX over two fields is</p> | + | <p>The function for using <code>MAX</code> over two fields is</p> |
max(x,y) = (x + y + ABS(x-y))/2 | max(x,y) = (x + y + ABS(x-y))/2 | ||
| − | <p>The function for using MIN over two fields is</p> | + | <p>The function for using <code>MIN</code> over two fields is</p> |
min(x,y) = (x + y - ABS(x-y))/2 | min(x,y) = (x + y - ABS(x-y))/2 | ||
</div> | </div> | ||
<source lang='sql' class='def'>SELECT id, x, y, (x+y+ABS(x-y))/2 | <source lang='sql' class='def'>SELECT id, x, y, (x+y+ABS(x-y))/2 | ||
FROM t</source> | FROM t</source> | ||
| − | <div class="ecomm e-mysql" style="display: none">In MySQL you can also use the GREATEST or LEAST functions to do this.</div> | + | <div class="ecomm e-mysql" style="display: none">In MySQL you can also use the <code>GREATEST</code> or <code>LEAST</code> functions to do this.</div> |
| − | <div class="ecomm e-oracle" style="display: none">In Oracle you can also use the GREATEST or LEAST functions to do this.</div> | + | <div class="ecomm e-oracle" style="display: none">In Oracle you can also use the <code>GREATEST</code> or <code>LEAST</code> functions to do this.</div> |
{{Hacks Ref}} | {{Hacks Ref}} | ||
Revision as of 14:59, 30 July 2012
Calculate the maximum or minimum of two fields
DROP TABLE t
CREATE TABLE t( id VARCHAR(10), x INTEGER, y INTEGER ); INSERT INTO t VALUES ('A',1,2); INSERT INTO t VALUES ('B',4,3); INSERT INTO t VALUES ('C',5,5);
The function for using MAX over two fields is
max(x,y) = (x + y + ABS(x-y))/2
The function for using MIN over two fields is
min(x,y) = (x + y - ABS(x-y))/2
SELECT id, x, y, (x+y+ABS(x-y))/2 FROM t
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
