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A numeric string as array key in PHP
...around is:
$id = 55;
$array = array(
" $id" => $value
);
The space char (prepend) is a good solution because keep the int conversion:
foreach( $array as $key => $value ) {
echo $key;
}
You'll see 55 as int.
s...
must appear in the GROUP BY clause or be used in an aggregate function
...
Yes, this is a common aggregation problem. Before SQL3 (1999), the selected fields must appear in the GROUP BY clause[*].
To workaround this issue, you must calculate the aggregate in a sub-query and then join it with itself to get the additional columns you'd need to show:
SELECT m.cname...
How do I perform an IF…THEN in an SQL SELECT?
How do I perform an IF...THEN in an SQL SELECT statement?
30 Answers
30
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How to concatenate text from multiple rows into a single text string in SQL server?
...y, John, Sam
2 Alaina, Edward
I used the following T-SQL:
SELECT Main.SubjectID,
LEFT(Main.Students,Len(Main.Students)-1) As "Students"
FROM
(
SELECT DISTINCT ST2.SubjectID,
(
SELECT ST1.StudentName + ',' AS [text()]
FR...
Count number of records returned by group by
...
You can do both in one query using the OVER clause on another COUNT
select
count(*) RecordsPerGroup,
COUNT(*) OVER () AS TotalRecords
from temptable
group by column_1, column_2, column_3, column_4
share
...
What is the purpose of Order By 1 in SQL select statement?
...number stands for the column based on the number of columns defined in the SELECT clause. In the query you provided, it means:
ORDER BY A.PAYMENT_DATE
It's not a recommended practice, because:
It's not obvious/explicit
If the column order changes, the query is still valid so you risk ordering ...
Using LIMIT within GROUP BY to get N results per group?
...to get all years into a single column, grouped by id and ordered by rate:
SELECT id, GROUP_CONCAT(year ORDER BY rate DESC) grouped_year
FROM yourtable
GROUP BY id
Result:
-----------------------------------------------------------
| ID | GROUPED_YEAR |...
SQL query to find record with ID not in another table
...
Try this
SELECT ID, Name
FROM Table1
WHERE ID NOT IN (SELECT ID FROM Table2)
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improve this answer
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Is there any difference between GROUP BY and DISTINCT
...CT and distinct by UNION cause an oracle error, but GROUP BY worked; I was selecting only 1 column from a view and not using any aggregation; I'm still baffled why it required it, but it does confirm there is some difference in the execution. As others point out, it also lets you GROUP BY columns no...
Changing one character in a string
What is the easiest way in Python to replace a character in a string?
11 Answers
11
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