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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
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Getting list of lists into pandas DataFrame
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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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LEFT JOIN vs. LEFT OUTER JOIN in SQL Server
... at the answer I left on this other SO question: SQL left join vs multiple tables on FROM line?.
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What makes a SQL statement sargable?
...sts. It will literally have to evaluate this function for every row of the table. Much better to use:
WHERE myDate >= '01-01-2008' AND myDate < '01-01-2009'
Some other examples:
Bad: Select ... WHERE isNull(FullName,'Ed Jones') = 'Ed Jones'
Fixed: Select ... WHERE ((FullName = 'Ed Jones') ...
How to Delete using INNER JOIN with SQL Server?
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You need to specify what table you are deleting from, here is a version with an alias:
DELETE w
FROM WorkRecord2 w
INNER JOIN Employee e
ON EmployeeRun=EmployeeNo
WHERE Company = '1' AND Date = '2013-05-06'
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Making a UITableView scroll when text field is selected
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If you use UITableViewController instead of UIViewController, it will automatically do so.
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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 can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
My table is:
18 Answers
18
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Difference between clustered and nonclustered index [duplicate]
I need to add proper index to my tables and need some help.
6 Answers
6
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What's wrong with nullable columns in composite primary keys?
...n optionally be related to B, the clean solution is to create a resolution table (let's say AB). That table would link A with B: If there is a relationship then it would contain a record, if there isn't then it would not.
sh...