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Pandas groupby: How to get a union of strings
I have a dataframe like this:
8 Answers
8
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What's the Linq to SQL equivalent to TOP or LIMIT/OFFSET?
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In VB:
from m in MyTable
take 10
select m.Foo
This assumes that MyTable implements IQueryable. You may have to access that through a DataContext or some other provider.
It also assumes that Foo is a column in MyTable that gets mapped to a property name.
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SQL SELECT WHERE field contains words
I need a select which would return results like this:
15 Answers
15
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Abusing the algebra of algebraic data types - why does this work?
...gard that for the sake of simplicity.
A few initial points:
Note that "union" is probably not the best term for A+B here--that's specifically a disjoint union of the two types, because the two sides are distinguished even if their types are the same. For what it's worth, the more common term is ...
What is the difference between 'protected' and 'protected internal'?
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The "protected internal" access modifier is a union of both the "protected" and "internal" modifiers.
From MSDN, Access Modifiers (C# Programming Guide):
protected:
The type or member can be accessed only by code in the same class or
struct, or in a class that is...
Where to put include statements, header or source?
...ing things like typedefs for integer sizes and a few common structures and unions [e.g.
typedef union {
unsigned long l;
unsigned short lw[2];
unsigned char lb[4];
} U_QUAD;
(Yes, I know I'd be in trouble if I moved to a big-endian architecture, but since my compiler doesn't allow anonymou...
Drop all tables whose names begin with a certain string
...n one in the database.
DECLARE @cmd varchar(4000)
DECLARE cmds CURSOR FOR
SELECT 'drop table [' + Table_Name + ']'
FROM INFORMATION_SCHEMA.TABLES
WHERE Table_Name LIKE 'prefix%'
OPEN cmds
WHILE 1 = 1
BEGIN
FETCH cmds INTO @cmd
IF @@fetch_status != 0 BREAK
EXEC(@cmd)
END
CLOSE cmds;
DEA...
How to initialize a struct in accordance with C programming language standards
...ne to use a designated initializer to initialize members of a structure or union as follows:
MY_TYPE a = { .stuff = 0.456, .flag = true, .value = 123 };
It is defined in paragraph 7, section 6.7.8 Initialization of ISO/IEC 9899:1999 standard as:
If a designator has the form
. identifier
t...
SQL Update with row_number()
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One more option
UPDATE x
SET x.CODE_DEST = x.New_CODE_DEST
FROM (
SELECT CODE_DEST, ROW_NUMBER() OVER (ORDER BY [RS_NOM]) AS New_CODE_DEST
FROM DESTINATAIRE_TEMP
) x
share
|
im...
How to list the tables in a SQLite database file that was opened with ATTACH?
...quently, if you used
ATTACH some_file.db AS my_db;
then you need to do
SELECT name FROM my_db.sqlite_master WHERE type='table';
Note that temporary tables don't show up with .tables either: you have to list sqlite_temp_master for that:
SELECT name FROM sqlite_temp_master WHERE type='table';
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