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Add Foreign Key to existing table
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To add a foreign key (grade_id) to an existing table (users), follow the following steps:
ALTER TABLE users ADD grade_id SMALLINT UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE users ADD CONSTRAINT fk_grade_id FOREIGN KEY (grade_id) REFERENCES grades(id);
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From io.Reader to string in Go
...byte to a string, you could change the contents of the string. However, go allows you to disable the type safety mechanisms using the unsafe package. Use the unsafe package at your own risk. Hopefully the name alone is a good enough warning. Here is how I would do it using unsafe:
buf := new(bytes....
Current time in microseconds in java
...ble on many platforms, 2) returning millisecond accuracy in a microsecond call leads to application portability issues.
– Stephen C
Nov 11 '09 at 4:17
9
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Disable Drag and Drop on HTML elements?
...e :active pseudo-class being applied to the element. This means I can't really use it for my links.
– Andy E
Oct 6 '11 at 11:28
3
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What's the opposite of chr() in Ruby?
In many languages there's a pair of functions, chr() and ord() , which convert between numbers and character values. In some languages, ord() is called asc() .
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How to restore to a different database in sql server?
...mpCopy with the contents of your.bak.
Example (restores a backup of a db called 'creditline' to 'MyTempCopy';
RESTORE FILELISTONLY FROM DISK='e:\mssql\backup\creditline.bak'
>LogicalName
>--------------
>CreditLine
>CreditLine_log
RESTORE DATABASE MyTempCopy FROM DISK='e:\mssql\backu...
How can I give eclipse more memory than 512M?
I have following setup, but when I put 1024 and replace all 512 with 1024, then eclipse won't start at all. How can I have more than 512M memory for my eclipse JVM?
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Errors: “INSERT EXEC statement cannot be nested.” and “Cannot use the ROLLBACK statement within an I
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do you have any idea what the technical reason is for not allowing it? I can't find any info on this.
– jtate
Feb 15 '19 at 21:29
1
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How to have stored properties in Swift, the same way I had on Objective-C?
...n't work : static var means that the value of the property is the same for all instance
– Fry
Mar 8 '17 at 15:40
@fry ...
I need to generate uuid for my rails application. What are the options(gems) I have? [duplicate]
...to be in Ruby 1.8.7. Looks like it was added in 1.9.3: apidock.com/ruby/v1_9_3_392/SecureRandom/uuid/class
– existentialmutt
Aug 25 '14 at 17:31
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