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Foreign keys in mongo?
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You may be interested in using a ORM like Mongoid or MongoMapper.
http://mongoid.org/docs/relations/referenced/1-n.html
In a NoSQL database like MongoDB there are not 'tables' but collections. Documents are grouped inside Collections. You can have any kind of document ...
Pandas percentage of total with groupby
...te the percentage in a simpler way -- just groupby the state_office and divide the sales column by its sum. Copying the beginning of Paul H's answer:
# From Paul H
import numpy as np
import pandas as pd
np.random.seed(0)
df = pd.DataFrame({'state': ['CA', 'WA', 'CO', 'AZ'] * 3,
'...
How to implement WiX installer upgrade?
...a localised error message, and also prevents upgrading an already existing identical version (i.e. only lower versions are upgraded):
<MajorUpgrade
AllowDowngrades="no" DowngradeErrorMessage="!(loc.NewerVersionInstalled)"
AllowSameVersionUpgrades="no"
/>
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Cannot insert explicit value for identity column in table 'table' when IDENTITY_INSERT is set to OFF
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You're inserting values for OperationId that is an identity column.
You can turn on identity insert on the table like this so that you can specify your own identity values.
SET IDENTITY_INSERT Table1 ON
INSERT INTO Table1
/*Note the column list is REQUIRED he...
How to handle many-to-many relationships in a RESTful API?
... resources by encoding those relationships as links. Thus, a team can be said to have a document resource (/team/{id}/players) that is a list of links to players (/player/{id}) on the team, and a player can have a document resource (/player/{id}/teams) that is a list of links to teams that the playe...
Append text to input field
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$('#input-field-id').val($('#input-field-id').val() + 'more text');
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<input id="input-field-id" />
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How to create a unique index on a NULL column?
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It seems the content of the link you provided was actually (partially) copied without attribution from here: decipherinfosys.wordpress.com/2007/11/30/…
– Tom Juergens
Feb 25 '10 at 9:58
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Update a table using JOIN in SQL Server?
...umn to the aggregate of another column (which violates the principle of avoiding storing redundant data), you can use a CTE (common table expression) - see here and here for more details:
;WITH t2 AS
(
SELECT [key], CalculatedColumn = SUM(some_column)
FROM dbo.table2
GROUP BY [key]
)
UPDA...
Get users by name property using Firebase
.... At a high level, Firebase is a tree-structured NoSQL data store, and provides a few simple primitives for managing lists of data:
Write to Firebase with a unique, known key:
ref.child('users').child('123').set({ "first_name": "rob", "age": 28 })
Append to lists with an auto-generated key that ...
How to search by key=>value in a multidimensional array in PHP
...ny fast way to get all subarrays where a key value pair was found in a multidimensional array? I can't say how deep the array will be.
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