# Help me on how to

**URL:** <https://www.ruby-forum.com/t/help-me-on-how-to/178776>\
**Category:** Rails\
**Created:** [November 11, 2009, 6:03am UTC](https://www.ruby-forum.com/t/help-me-on-how-to/178776 "2009-11-11T06:03:18Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![newb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/2acd7d/32.png) [@newb](https://www.ruby-forum.com/u/newb)\
**Post date:** [November 11, 2009, 6:03am UTC](https://www.ruby-forum.com/t/help-me-on-how-to/178776/1 "2009-11-11T06:03:18Z")

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i want to check the given mysql database is exists or not using rails…  
i searched the net and found the below  
SELECT SCHEMA\_NAME FROM INFORMATION\_SCHEMA.SCHEMATA WHERE SCHEMA\_NAME =  
‘testdb’  
this is works in query browser.

like wise i can i check in rails …  
pls guide me on this

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<div class="post-metadata">

**Author:** ![newb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/2acd7d/32.png) [@newb](https://www.ruby-forum.com/u/newb)\
**Post date:** [November 11, 2009, 6:27am UTC](https://www.ruby-forum.com/t/help-me-on-how-to/178776/2 "2009-11-11T06:27:59Z")

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Hi  
Is it the db details you specified in database.yml? If yes you can  
get details from  
ActiveRecord::Base.configurations

An example is  
ActiveRecord::Base.configurations[‘development’][‘database’]

Sijo

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<div class="post-metadata">

**Author:** ![newb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/2acd7d/32.png) [@newb](https://www.ruby-forum.com/u/newb)\
**Post date:** [November 11, 2009, 6:35am UTC](https://www.ruby-forum.com/t/help-me-on-how-to/178776/3 "2009-11-11T06:35:58Z")

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Sijo k g wrote:

> Hi  
> Is it the db details you specified in database.yml? If yes you can  
> get details from  
> ActiveRecord::Base.configurations
> 
> An example is  
> ActiveRecord::Base.configurations[‘development’][‘database’]
> 
> Sijo

Thanks for the reply…  
no i dont want to check the db which is specified in the yml file.  
in the same port, i ll create a new database to move existing records.  
for that i want to check whether the given db is alive or not

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<div class="post-metadata">

**Author:** ![newb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/2acd7d/32.png) [@newb](https://www.ruby-forum.com/u/newb)\
**Post date:** [November 11, 2009, 7:08am UTC](https://www.ruby-forum.com/t/help-me-on-how-to/178776/4 "2009-11-11T07:08:22Z")

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Hi

> no i dont want to check the db which is specified in the yml file.  
> in the same port, i ll create a new database to move existing records.  
> for that i want to check whether the given db is alive or not

You can directly execute query from with in rails  
ActiveRecord::Base.connection.execute(sql)

```
  May be there some other solutions to your question which i am not 

```

aware of

Sijo

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<div class="post-metadata">

**Author:** ![newb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/2acd7d/32.png) [@newb](https://www.ruby-forum.com/u/newb)\
**Post date:** [November 11, 2009, 7:50am UTC](https://www.ruby-forum.com/t/help-me-on-how-to/178776/5 "2009-11-11T07:50:57Z")

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Sijo k g wrote:

> Hi
> 
> > no i dont want to check the db which is specified in the yml file.  
> > in the same port, i ll create a new database to move existing records.  
> > for that i want to check whether the given db is alive or not
> 
> You can directly execute query from with in rails  
> ActiveRecord::Base.connection.execute(sql)
> 
> ```
> May be there some other solutions to your question which i am not 
> 
> ```
> 
> aware of
> 
> Sijo

Thank u  
sql = “SELECT SCHEMA\_NAME FROM INFORMATION\_SCHEMA.SCHEMATA WHERE  
SCHEMA\_NAME ‘c1’”  
@s = ActiveRecord::Base.connection.execute(sql)  
how to know the result.  
it always retuns not nil even for wrong db(which is not exists)  
how can i check it up

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<div class="post-metadata">

**Author:** ![newb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/2acd7d/32.png) [@newb](https://www.ruby-forum.com/u/newb)\
**Post date:** [November 11, 2009, 8:53am UTC](https://www.ruby-forum.com/t/help-me-on-how-to/178776/6 "2009-11-11T08:53:31Z")

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Hi

> sql = “SELECT SCHEMA\_NAME FROM INFORMATION\_SCHEMA.SCHEMATA WHERE  
> SCHEMA\_NAME ‘c1’”  
> @s = ActiveRecord::Base.connection.execute(sql)  
> how to know the result.  
> it always retuns not nil even for wrong db(which is not exists)  
> how can i check it up

One is @s.collect.size for 0

Sijo