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Eager load polymorphic
...d is unable to build the join without additional information.
There is no table called reviewable
To solve this issue, you need to explicitly define the relationship between Review and Shop.
class Review < ActiveRecord::Base
belongs_to :user
belongs_to :reviewable, polymorphic: true
...
Getting list of lists into pandas DataFrame
...
Call the pd.DataFrame constructor directly:
df = pd.DataFrame(table, columns=headers)
df
Heading1 Heading2
0 1 2
1 3 4
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Django dump data for a single model?
...Django dumpdata management command allows you to dump data from individual tables:
./manage.py dumpdata myapp1 myapp2.my_model
You can also separate multiple apps and models on the command line. Here's the canonical definition:
django-admin dumpdata [app_label[.ModelName] [app_label[.ModelName] ...
Detect if value is number in MySQL
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This should work in most cases.
SELECT * FROM myTable WHERE concat('',col1 * 1) = col1
It doesn't work for non-standard numbers like
1e4
1.2e5
123. (trailing decimal)
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PadLeft function in T-SQL
I have the following table A:
17 Answers
17
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Benchmarking (python vs. c++ using BLAS) and (numpy)
... new machines I also ran the benchmark for matrix sizes 5000 and 8000.
The table below includes the benchmark results from the original answer (renamed: MKL --> Nehalem MKL, Netlib Blas --> Nehalem Netlib BLAS, etc)
Single threaded performance:
Multi threaded performance (8 threads):
T...
When to use a “has_many :through” relation in Rails?
...p
# has attributes for date_joined and role
end
This introduces a new table, and eliminates the group_id column from the user's table.
The problem with this code is that you'd have to update every where else you use the user class and change it:
user.groups.first.name
# becomes
user.group_m...
how to display full stored procedure code?
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just in case anyone is confused as to where that table is: pg_catalog -> system table -> pg_proc
– Dimitris
Aug 24 '12 at 7:19
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Difference between “read commited” and “repeatable read”
..., will find the Same data, data is free to change after it was read.
Repeatable read is a higher isolation level, that in addition to the guarantees of the read committed level, it also guarantees that any data read cannot change, if the transaction reads the same data again, it will find the previ...
Getting result of dynamic SQL into a variable for sql-server
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dynamic version
ALTER PROCEDURE [dbo].[ReseedTableIdentityCol](@p_table varchar(max))-- RETURNS int
AS
BEGIN
-- Declare the return variable here
DECLARE @sqlCommand nvarchar(1000)
DECLARE @maxVal INT
set @sqlCommand = 'SELECT @maxVal...