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Drop data frame columns by name
...op=FALSE to keep R from converting your data frame to a vector if you only select a single column. Don't forget that data frames are lists, so list selection (one-dimensional like I did) works perfectly well and always returns a list. Or a data frame in this case, which is why I prefer to use it.
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How to create a project from existing source in Eclipse and then find it?
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Right-click in the package explorer and select New - Java Project
Create the new project Game
Open the new project in the package explorer - you should see only the source folder called src (there's nothing inside yet)
Open a file Explorer (e.g. Windows Explorer) a...
How to 'insert if not exists' in MySQL?
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Solution:
INSERT INTO `table` (`value1`, `value2`)
SELECT 'stuff for value1', 'stuff for value2' FROM DUAL
WHERE NOT EXISTS (SELECT * FROM `table`
WHERE `value1`='stuff for value1' AND `value2`='stuff for value2' LIMIT 1)
Explanation:
The innermost query
SELECT *...
Get list of databases from SQL Server
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Execute:
SELECT name FROM master.sys.databases
This the preferred approach now, rather than dbo.sysdatabases, which has been deprecated for some time.
Execute this query:
SELECT name FROM master.dbo.sysdatabases
or if you pref...
Saving results with headers in Sql Server Management Studio
...reopen SSMS after changing this option.
On the SQL Editor Toolbar you can select save to file without having to restart SSMS
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How to display default text “--Select Team --” in combo box on pageload in WPF?
...ComboBox Name="MyComboBox"
IsEditable="True"
IsReadOnly="True"
Text="-- Select Team --" />
You'll obviously need to add your other options, but this is probably the simplest way to do it.
There is however one downside to this method which is while the text inside your combo box will not be ...
Eclipse fonts and background color
...→ General → Editors → Text Editors
Browse Appearance color options
Select background color options, uncheck default, change to black
Select background color options, uncheck default, change to colour of choice
To change text colours
Open Java → Editor → Syntax Colouring
Select ele...
How to check if mysql database exists
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SELECT SCHEMA_NAME
FROM INFORMATION_SCHEMA.SCHEMATA
WHERE SCHEMA_NAME = 'DBName'
If you just need to know if a db exists so you won't get an error when you try to create it, simply use (From here):
CREATE DATABASE IF NO...
List of Stored Procedures/Functions Mysql Command Line
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For view procedure in name wise
select name from mysql.proc
below code used to list all the procedure and below code is give same result as show procedure status
select * from mysql.proc
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Create code first, many to many, with additional fields in association table
...OfMembers = context.Members
.Where(m => m.LastName == "Smith")
.SelectMany(m => m.MemberComments.Select(mc => mc.Comment))
.ToList();
... or ...
var commentsOfMembers = context.MemberComments
.Where(mc => mc.Member.LastName == "Smith")
.Select(mc => mc.Comment)
...