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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...
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...
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...
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 '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 *...
How do I remove javascript validation from my eclipse project?
...validation all together is too drastic. Fortunately with Eclipse, you can selectively remove some JavaScript sources from validation.
Right-click your project.
Navigate to: Properties → JavaScript → Include Path
Select Source tab. (It looks identical to Java Build Path Source tab.)
Expand Jav...
SQL Server: Examples of PIVOTing String data
...l as numbers. This query will only require the table to be scanned once.
SELECT Action,
MAX( CASE data WHEN 'View' THEN data ELSE '' END ) ViewCol,
MAX( CASE data WHEN 'Edit' THEN data ELSE '' END ) EditCol
FROM t
GROUP BY Action
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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...
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)
...