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How to include “zero” / “0” results in COUNT aggregate?
...n outer join for this (and you need to use person as the "driving" table)
SELECT person.person_id, COUNT(appointment.person_id) AS "number_of_appointments"
FROM person
LEFT JOIN appointment ON person.person_id = appointment.person_id
GROUP BY person.person_id;
The reason why this is working, i...
How can I create a copy of an Oracle table without copying the data?
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Just use a where clause that won't select any rows:
create table xyz_new as select * from xyz where 1=0;
Limitations
The following things will not be copied to the new table:
sequences
triggers
indexes
some constraints may not be copied
materialized view...
MySQL SELECT WHERE datetime matches day (and not necessarily time)
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NEVER EVER use a selector like DATE(datecolumns) = '2012-12-24' - it is a performance killer:
it will calculate DATE() for all rows, including those, that don't match
it will make it impossible to use an index for the query
It is much fas...
Check if all checkboxes are selected
How do I check if all checkboxes with class="abc" are selected?
9 Answers
9
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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...
How do I get textual contents from BLOB in Oracle SQL
...S of the text stored in the BLOB, CS of the database used for VARCHAR2) :
select utl_raw.cast_to_varchar2(dbms_lob.substr(BLOB_FIELD)) from TABLE_WITH_BLOB where ID = '<row id>';
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Select a Dictionary with LINQ
I have used the "select" keyword and extension method to return an IEnumerable<T> with LINQ, but I have a need to return a generic Dictionary<T1, T2> and can't figure it out. The example I learned this from used something in a form similar to the following:
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DataSet panel (Report Data) in SSRS designer is gone
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With a report (rdl) file selected in your solution, select View and then Report Data.
It is a shortcut of Ctrl+Alt+D.
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git selective revert local changes from a file
...fore checkout -p was introduced):
You can do it like this:
git add -i
(select the hunks you want to keep)
git commit -m "tmp"
Now you have a commit with only the changes you want to keep, and the rest is unstaged.
git reset --hard HEAD
At this point, uncommitted changes have been discarded...
convert a list of objects from one type to another using lambda expression
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Try the following
var targetList = origList
.Select(x => new TargetType() { SomeValue = x.SomeValue })
.ToList();
This is using a combination of Lambdas and LINQ to achieve the solution. The Select function is a projection style method which will apply the passe...