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Selecting data from two different servers in SQL Server
...edserver.
You only have to set up one. Once you have that, you can call a table on the other server like so:
select
*
from
LocalTable,
[OtherServerName].[OtherDB].[dbo].[OtherTable]
Note that the owner isn't always dbo, so make sure to replace it with whatever schema you use.
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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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How to delete from multiple tables in MySQL?
I am trying to delete from a few tables at once. I've done a bit of research, and came up with this
7 Answers
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MySQL how to join tables on two fields
I have two tables with date and id fields. I want to join on both fields. I tried
3 Answers
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How to drop multiple columns in postgresql
I want to drop 200 columns in my table in PostgreSQL. I tried:
2 Answers
2
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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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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') ...
Remove rows with all or some NAs (missing values) in data.frame
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If performance is a priority, use data.table and na.omit() with optional param cols=.
na.omit.data.table is the fastest on my benchmark (see below), whether for all columns or for select columns (OP question part 2).
If you don't want to use data.table, use comple...
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
share
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Removing duplicate rows from table in Oracle
I'm testing something in Oracle and populated a table with some sample data, but in the process I accidentally loaded duplicate records, so now I can't create a primary key using some of the columns.
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