Difference between revisions of "Running Total"

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Keep a running total
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<p>In this example you are shown how to get a running total in a set of results.</p>
 +
<p>Table 1 shows the results without the running total and Table 2 shows what we get with the running total.</p>
 +
<div class="ref_section">
 +
<table class= "db_ref">
 +
<caption>Table 1</caption>
 +
<tr><th align='center'>'''whn'''</th><th>'''description'''</th><th align='center'>'''amount'''</th></tr>
 +
<tr><td align='left'>2006-11-01</td><td align='left'>Wages</td><td align='left'>50</td></tr>
 +
<tr><td align='left'>2006-11-02</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-03</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-04</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-05</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-06</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
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</table>
 +
<table class="db_ref">
 +
<caption>Table 2</caption>
 +
<tr><th align='center'>'''whn'''</th><th>'''description'''</th><th align='center'>'''amount'''</th></tr>
 +
<tr><td align='left'>2006-11-01</td><td align='left'>Wages</td><td align='left'>50</td></tr>
 +
<tr><td align='left'>2006-11-02</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-03</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-04</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-05</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
<tr><td align='left'>2006-11-06</td><td align='left'>Company Store</td><td align='left'>-10</td></tr>
 +
</table>
 +
</div>
 
<div class='ht'>
 
<div class='ht'>
 
<div class=params>schema:scott</div>
 
<div class=params>schema:scott</div>
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   whn DATE,
 
   whn DATE,
 
   description VARCHAR(20),
 
   description VARCHAR(20),
   amount INTEGER );
+
   amount TEXT );
INSERT INTO transact VALUES ((2006,11,01),'Wages',50);
+
INSERT INTO transact VALUES ('2006-11-01','Wages',50);
INSERT INTO transact VALUES ((2006,11,02),'Company Store',-10);
+
INSERT INTO transact VALUES ('2006-11-02','Company Store',-10);
INSERT INTO transact VALUES ((2006,11,03),'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 ('2006-11-04','Company Store',-10);
INSERT INTO transact VALUES ((2006,11,05),'Company Store',-10);
+
INSERT INTO transact VALUES ('2006-11-05','Company Store',-10);
INSERT INTO transact VALUES ((2006,11,06),'Company Store',-10);
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INSERT INTO transact VALUES ('2006-11-06','Company Store',-10);
 
</source>
 
</source>
 
<div>
 
<div>
Line 35: Line 58:
 
@accumulator:=@accumulator+amount RunningTotal
 
@accumulator:=@accumulator+amount RunningTotal
 
FROM transact</div>
 
FROM transact</div>
<div class="ecomm e-oracle" style="display: none">In Oracle the following query works:
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<div class="ecomm e-oracle" style="display: none">In Oracle the following query also works:
 
SELECT whn, amount, SUM(amount) OVER (ORDER BY whn)
 
SELECT whn, amount, SUM(amount) OVER (ORDER BY whn)
 
FROM transact</div>
 
FROM transact</div>
 
</div>
 
</div>
 
{{Hacks Ref}}
 
{{Hacks Ref}}

Revision as of 11:11, 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.

Table 1
whndescriptionamount
2006-11-01Wages50
2006-11-02Company Store-10
2006-11-03Company Store-10
2006-11-04Company Store-10
2006-11-05Company Store-10
2006-11-06Company Store-10
Table 2
whndescriptionamount
2006-11-01Wages50
2006-11-02Company Store-10
2006-11-03Company Store-10
2006-11-04Company Store-10
2006-11-05Company Store-10
2006-11-06Company Store-10
schema:scott
DROP TABLE transact
 CREATE TABLE transact(
  whn DATE,
  description VARCHAR(20),
  amount TEXT );
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
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