大约有 40,000 项符合查询结果（耗时：0.0262秒） [XML]
Pad a string with leading zeros so it's 3 characters long in SQL Server 2008
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If the field is already a string, this will work
SELECT RIGHT('000'+ISNULL(field,''),3)
If you want nulls to show as '000'
It might be an integer -- then you would want
SELECT RIGHT('000'+CAST(field AS VARCHAR(3)),3)
As required by the question this answer only w...
Extracting specific columns in numpy array
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I assume you wanted columns 1 and 9?
To select multiple columns at once, use
X = data[:, [1, 9]]
To select one at a time, use
x, y = data[:, 1], data[:, 9]
With names:
data[:, ['Column Name1','Column Name2']]
You can get the names from data.dtype.names…
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Convert Unix timestamp into human readable date using MySQL
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Use FROM_UNIXTIME():
SELECT
FROM_UNIXTIME(timestamp)
FROM
your_table;
See also: MySQL documentation on FROM_UNIXTIME().
share
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improve...
Inner join vs Where
... for the query using the inner join:
-- with inner join
EXPLAIN PLAN FOR
SELECT * FROM table1 t1
INNER JOIN table2 t2 ON t1.id = t2.id;
SELECT *
FROM TABLE (DBMS_XPLAN.DISPLAY);
-- 0 select statement
-- 1 hash join (access("T1"."ID"="T2"."ID"))
-- 2 table access full table1
-- 3 table access ful...
Select distinct using linq [duplicate]
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myList.GroupBy(test => test.id)
.Select(grp => grp.First());
Edit: as getting this IEnumerable<> into a List<> seems to be a mystery to many people, you can simply write:
var result = myList.GroupBy(test => test.id)
.S...
JUnit 4 Test Suites
...lipse:
In the 'Package Explorer' view of the eclipse 'Java' perspective,
select your unit test(s) in their package, inside the eclipse java
project.
Right-click on any one of the selected tests.
In the pop-up menu, select New, Other…
Open the ‘Java’ folder, then open the ‘JUnit’ folder...
How to open existing project in Eclipse
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Project > Import > General > Select Root Directory > (do NOT select copy projects into workspace). This is useful if you use Eclipse outside scope of Java project as well, such as Ruby projects or C projects.
– JohnMerlino
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jQuery selector regular expressions
...d or regular expressions (not sure on the exact terminology) with a jQuery selector.
10 Answers
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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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COUNT DISTINCT with CONDITIONS
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You can try this:
select
count(distinct tag) as tag_count,
count(distinct (case when entryId > 0 then tag end)) as positive_tag_count
from
your_table_name;
The first count(distinct...) is easy.
The second one, looks somewhat complex...