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How to delete from select in MySQL?
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SELECT (sub)queries return result sets. So you need to use IN, not = in your WHERE clause.
Additionally, as shown in this answer you cannot modify the same table from a subquery within the same query. However, you can either...
Using group by on multiple columns
..., to do with who is attending what subject at a university:
Table: Subject_Selection
+---------+----------+----------+
| Subject | Semester | Attendee |
+---------+----------+----------+
| ITB001 | 1 | John |
| ITB001 | 1 | Bob |
| ITB001 | 1 | Mickey |
| ITB001 ...
How to check if a table exists in a given schema
... whether a table (or view) exists, and the current user has access to it?
SELECT EXISTS (
SELECT FROM information_schema.tables
WHERE table_schema = 'schema_name'
AND table_name = 'table_name'
);
The information schema is mainly useful to stay portable across major versions and...
How to keep onItemSelected from firing off on a newly instantiated Spinner?
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I would have expected your solution to work -- I though the selection event would not fire if you set the adapter before setting up the listener.
That being said, a simple boolean flag would allow you to detect the rogue first selection event and ignore it.
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How can I remove a trailing newline?
...s the Python equivalent of Perl's chomp function, which removes the last character of a string if it is a newline?
28 Ans...
quick random row selection in Postgres
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You might want to experiment with OFFSET, as in
SELECT myid FROM mytable OFFSET floor(random()*N) LIMIT 1;
The N is the number of rows in mytable. You may need to first do a SELECT COUNT(*) to figure out the value of N.
Update (by Antony Hatchkins)
You must use floor he...
Any way to make a WPF textblock selectable?
How to allow TextBlock 's text to be selectable?
15 Answers
15
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Case in Select Statement
I have an SQL statement that has a CASE from SELECT and I just can't get it right. Can you guys show me an example of CASE where the cases are the conditions and the results are from the cases. For example:
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Generate a random number in the range 1 - 10
... 1 and 10 you mean any float that is >= 1 and < 10, then it's easy:
select random() * 9 + 1
This can be easily tested with:
# select min(i), max(i) from (
select random() * 9 + 1 as i from generate_series(1,1000000)
) q;
min | max
-----------------+------------------...
How to vertically align text inside a flexbox?
...-items: baseline. Good for different heights coming from different unicode chars etc.
– qräbnö
Jan 7 '19 at 16:50
1
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