Difference between revisions of "Running Total"
| Line 41: | Line 41: | ||
version can be called table x and table y.</p> | version can be called table x and table y.</p> | ||
SELECT x.whn, x.description, x.amount, | SELECT x.whn, x.description, x.amount, | ||
| − | + | SUM(y.amount) AS balance | |
| − | + | FROM transact x JOIN transact y ON (x.whn>=y.whn) | |
| − | + | GROUP BY x.whn, x.description, x.amount | |
<p>If you want the money IN and money OUT to be separate a <code>CASE</code> expression can be used.</p> | <p>If you want the money IN and money OUT to be separate a <code>CASE</code> expression can be used.</p> | ||
</div> | </div> | ||
| − | <source lang='sql' class='def'>SELECT w AS dte, d AS description, | + | <source lang='sql' class='def'> |
| − | CASE WHEN (a>=0) THEN a ELSE NULL END AS moneyIN, | + | SELECT w AS dte, d AS description, |
| − | CASE WHEN (a<0) THEN a ELSE NULL END AS moneyOUT, | + | CASE WHEN (a>=0) THEN a ELSE NULL END AS moneyIN, |
| − | balance FROM | + | CASE WHEN (a<0) THEN a ELSE NULL END AS moneyOUT, |
| − | (SELECT x.whn AS w, x.description AS d, | + | balance |
| − | + | FROM | |
| − | FROM transact x JOIN transact y ON (x.whn>=y.whn) | + | (SELECT x.whn AS w, x.description AS d, |
| − | GROUP BY x.whn, x.description, x.amount) t</source> | + | x.amount AS a, SUM(y.amount) AS balance |
| + | FROM transact x JOIN transact y ON (x.whn>=y.whn) | ||
| + | GROUP BY x.whn, x.description, x.amount) t</source> | ||
<div class="ecomm e-mysql" style="display: none">In MySQL the following query also works: | <div class="ecomm e-mysql" style="display: none">In MySQL the following query also works: | ||
SELECT whn, description, amount, | SELECT whn, description, amount, | ||
Revision as of 13:43, 2 August 2012
In this example you are shown how to get a running total in a set of results.
Table 1 shows the results without the running total and Table 2 shows what we get with the running total.
| whn | description | amount |
|---|---|---|
| 2006-11-01 | Wages | 50 |
| 2006-11-02 | Company Store | -10 |
| 2006-11-03 | Company Store | -10 |
| 2006-11-04 | Company Store | -10 |
| 2006-11-05 | Company Store | -10 |
| 2006-11-06 | Company Store | -10 |
| whn | description | amount |
|---|---|---|
| 2006-11-01 | Wages | 50 |
| 2006-11-02 | Company Store | -10 |
| 2006-11-03 | Company Store | -10 |
| 2006-11-04 | Company Store | -10 |
| 2006-11-05 | Company Store | -10 |
| 2006-11-06 | Company Store | -10 |
DROP TABLE transact
CREATE TABLE transact( whn DATE, description VARCHAR(20), amount INTEGER ); INSERT INTO transact VALUES ('2006-11-01','Wages',50); INSERT INTO transact VALUES ('2006-11-02','Company Store',-10); INSERT INTO transact VALUES ('2006-11-03','Company Store',-10); INSERT INTO transact VALUES ('2006-11-04','Company Store',-10); INSERT INTO transact VALUES ('2006-11-05','Company Store',-10); INSERT INTO transact VALUES ('2006-11-06','Company Store',-10);
To calculate a running total a table needs to be joined to itself, each version can be called table x and table y.
SELECT x.whn, x.description, x.amount,
SUM(y.amount) AS balance
FROM transact x JOIN transact y ON (x.whn>=y.whn)
GROUP BY x.whn, x.description, x.amount
If you want the money IN and money OUT to be separate a CASE expression can be used.
SELECT w AS dte, d AS description, CASE WHEN (a>=0) THEN a ELSE NULL END AS moneyIN, CASE WHEN (a<0) THEN a ELSE NULL END AS moneyOUT, balance FROM (SELECT x.whn AS w, x.description AS d, x.amount AS a, SUM(y.amount) AS balance FROM transact x JOIN transact y ON (x.whn>=y.whn) GROUP BY x.whn, x.description, x.amount) 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 Keep a running total
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
