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How do I list all the columns in a table?
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For Oracle (PL/SQL)
SELECT column_name
FROM user_tab_cols
WHERE table_name = 'myTableName'
For MySQL
SHOW COLUMNS FROM table_name
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Pandas - Get first row value of a given column
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To select the ith row, use iloc:
In [31]: df_test.iloc[0]
Out[31]:
ATime 1.2
X 2.0
Y 15.0
Z 2.0
Btime 1.2
C 12.0
D 25.0
E 12.0
Name: 0, dtype: float64
To select the ith val...
SQL Server: Difference between PARTITION BY and GROUP BY
...y're used in different places. group by modifies the entire query, like:
select customerId, count(*) as orderCount
from Orders
group by customerId
But partition by just works on a window function, like row_number:
select row_number() over (partition by customerId order by orderId)
as OrderN...
Join between tables in two different databases?
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Yes, assuming the account has appropriate permissions you can use:
SELECT <...>
FROM A.table1 t1 JOIN B.table2 t2 ON t2.column2 = t1.column1;
You just need to prefix the table reference with the name of the database it resides in.
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What is the best way to add options to a select from a JavaScript object with jQuery?
What is the best method for adding options to a <select> from a JavaScript object using jQuery?
36 Answers
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Why can't radio buttons be “readonly”?
...ton by disabling only the un-checked radio buttons. It keeps the user from selecting a different value, and the checked value will always post on submit.
Using jQuery to make readonly:
$(':radio:not(:checked)').attr('disabled', true);
This approach also worked for making a select list readonly, ...
How to select unique records by SQL
When I perform "SELECT * FROM table" I got results like below:
8 Answers
8
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How can I indent multiple lines in Xcode?
When I select multiple lines of code and want to indent them as usual with TAB key, it just deletes them all. I come from Eclipse where I always did it that way. How's that done in Xcode? I hope not line by line ;)
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Initializing select with AngularJS and ng-repeat
I'm trying to get select-box to start off with a pre-filled option using ng-repeat with AngularJS 1.1.5. Instead the select always starts out with nothing selected. It also has an empty option, which I don't want. I think that there is a side effect of nothing being selected.
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LINQ's Distinct() on a particular property
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(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
{
HashSet<TKey> seenKeys = new HashSet<TKey>();
foreach (TSource element in source)
{
if (seenKeys.Add(keySelector(element)))
{
yield return element;
}
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