You can use tool [dpkg][1] for managing packages in Debian operating system.
## Example ##
`dpkg --get-selections | grep mysql` if it&#39;s listed as installed, you got it. Else you need to get it.


  [1]: https://en.wikipedia.org/wiki/Dpkg

&quot;mysql&quot; may be found even if mysql and mariadb is uninstalled, but not &quot;mysqld&quot;.

Faster than rpm -qa | grep mysqld is:

    which mysqld

Multiple ways of searching for the program.

Type `mysql` in your terminal, see the result.

Search the `/usr/bin`, `/bin` directories for the binary.

Type `apt-cache show mysql` to see if it is installed

`locate mysql`



With this command:

   

     dpkg -s mysql-server | grep Status

    # mysqladmin -u root -p status

Output:

    Enter password:
    Uptime: 4  Threads: 1  Questions: 62  Slow queries: 0  Opens: 51  Flush tables: 1  Open tables: 45  Queries per second avg: 15.500

It means MySQL serer is running

If server is not running then it will dump error as follows

    # mysqladmin -u root -p status

Output :

    mysqladmin: connect to server at &#39;localhost&#39; failed
    error: &#39;Can&#39;t connect to local MySQL server through socket &#39;/var/run/mysqld/mysqld.sock&#39; (2)&#39;
    Check that mysqld is running and that the socket: &#39;/var/run/mysqld/mysqld.sock&#39; exists!

So Under Debian Linux you can type following command

    # /etc/init.d/mysql status



**In an RPM-based Linux, you can check presence of MySQL like this:**

*rpm -qa | grep mysql*

**For debian or other dpkg-based systems, check like this:**
*
*dpkg -l mysql-server libmysqlclient*dev*
---------------------------------------

*

Try executing &#39;mysql&#39; or &#39;mysql -- version&#39; without quotes on terminal.
it will prompt version otherwise Command Not Found

What is the idiomatic python way to hide traceback errors unless a verbose or debug flag is set? 

Example code:

    their_md5 = &#39;c38f03d2b7160f891fc36ec776ca4685&#39;
    my_md5 = &#39;c64e53bbb108a1c65e31eb4d1bb8e3b7&#39; 
    if their_md5 != my_md5:
        raise ValueError(&#39;md5 sum does not match!&#39;)

Existing output now, but only desired when called with `foo.py --debug`:

    Traceback (most recent call last):
      File &quot;b:\code\apt\apt.py&quot;, line 1647, in &lt;module&gt;
        __main__.__dict__[command] (packages)
      File &quot;b:\code\apt\apt.py&quot;, line 399, in md5
        raise ValueError(&#39;md5 sum does not match!&#39;)
    ValueError: md5 sum does not match!

Desired normal output:

    ValueError: md5 sum does not match!

Here&#39;s a test script: https://gist.github.com/maphew/e3a75c147cca98019cd8


Hide traceback unless a debug flag is set

I saw this weird behaviour and I wonder if there&#39;s a reasonable explanation for this: 

When I put by ( by accident) an additional/extra semicolon in a function&#39;s local variable like: 

    public void MyMethod ()
    {
        int a = 1;;
        Console.WriteLine(a); //dummy 
    }
It does compile but it shows that it&#39;s redundant.

[![enter image description here][1]][1]

But when I did that with fields (also by accident) ,  I got an error (compilation) : 

[![enter image description here][2]][2]

**Question**

Is there any reason for this restrictiveness in fields ?

&lt;sup&gt;Nb I already know the other restrictiveness thing for not allowing `var` with fields. But here it&#39;s something different.&lt;/sup&gt;

  [1]: //i.stack.imgur.com/DAacI.png
  [2]: //i.stack.imgur.com/ZISN4.png

Why is ;; allowed after a local variable declaration, but not after a field declaration?

I need to check if mysql is installed on a ubuntu server. Is there a way to determine if mySql has been installed ? Thanks.

How can I check if mysql is installed on ubuntu?

<p>I need to check if mysql is installed on a ubuntu server. Is there a way to determine if mySql has been installed ? Thanks.</p>


I have a site that I&#39;ve built with Flask SQLAlchemy and SQLite, and need to switch to MySQL. I have migrated the database itself and have it running under MySQL, but 

 1. Can&#39;t figure out how to connect to the MySQL database (that is, what the `SQLALCHEMY_DATABASE_URI` should be) and
 2. Am unclear if any of my existing SQLAlchemy SQLite code will work with MySQL.

I suspect that (1) is fairly simple and just a matter of being shown how to map, for example, the contents of the connection dialog I use in my MySQL database tool to an appropriately formatted URL. But I&#39;m worried about (2), I had assumed that SQLAlchemy provided an abstraction layer so that [simple SQLAlchemy code such as][1] 

    from flask import Flask
    from flask.ext.sqlalchemy import SQLAlchemy
    
    app = Flask(__name__)
    app.config[&#39;SQLALCHEMY_DATABASE_URI&#39;] = &#39;sqlite:////tmp/test.db&#39;
    db = SQLAlchemy(app)
    
    
    class User(db.Model):
        id = db.Column(db.Integer, primary_key=True)
        username = db.Column(db.String(80), unique=True)
        email = db.Column(db.String(120), unique=True)
    
        def __init__(self, username, email):
            self.username = username
            self.email = email
    
        def __repr__(self):
            return &#39;&lt;User %r&gt;&#39; % self.username
    
    admin = User(&#39;admin&#39;, &#39;admin@example.com&#39;)
    
    db.session.add(admin)
    
    User.query.all()
    
    User.query.filter_by(username=&#39;admin&#39;).first()

wold work without any modifications other than an appropriate change to the database URI; but the [examples I&#39;ve found][2] for using SQLAlchemy with MySQL seem to use a completely different API.

Can I (2) migrate my Flask SQLAlchemy code to work with a MySQL database by simply changing the database URI and if so (1) what should that URI be?


  [1]: https://pythonhosted.org/Flask-SQLAlchemy/quickstart.html#a-minimal-application
  [2]: http://pylonsdevelopment.blogspot.com/2010/07/connecting-to-mysql-database-using.html

Switching from SQLite to MySQL with Flask SQLAlchemy

I have a set of Sequelize models. I want to use migrations, not DB Sync.

[Sequelize CLI][1] seems to be able to do this, according to [this article][2]:
&quot;When you use the CLI for the model generation, you will gain the migration scripts for free as well.&quot;

How to auto generate the migrations with Sequelize CLI from existing Sequelize models?


  [1]: https://github.com/sequelize/cli
  [2]: http://sequelizejs.com/articles/express

How to auto generate migrations with Sequelize CLI from Sequelize models?

I know that it looks like duplicate, but the solutions which I found don&#39;t work for me.
I uninstalled MySQL 5.1 and installed 5.6, and I would like to import a previously exported SQL file back. But there is some function which causes an error in that export file. 
I found and ran the command:

    ../bin mysql mysql_upgrade -uroot -p --force

but if I understand, it works only when upgrade, not with install. Is there some solution for me? 

I also removed the function definition from import file and import is done. But if I want to redefine that function manually it shows me the same error &quot;can not load from mysql.proc&quot;.
Function is here:

    DELIMITER $$
    
    CREATE FUNCTION `randStr250`(length int) RETURNS varchar(250) CHARSET utf8
    begin
      declare s varchar(250);
      declare i tinyint;
      set s=&quot;&quot;;
      if (length&lt;1 or length&gt;6) then
          set s=&quot;Parameter should be in range 1-6. Your value was out of this range.&quot;;
      else
        set i=0;
        while i&lt;length do
            set s=concat(s,sha1(now()));
            set i=i+1;
        end while;
      end if;
      return s;
    end $$
    
    DELIMITER ;

Cannot load from mysql.proc. The table is probably corrupted

Today I did a login as root into Ubuntu 14.04.1 LTS ll

and then `apt-get install mariadb-server` (without sudo but as root).

With `mySQL -h localhost -u root --password=&lt;PW&gt;` I got

&gt; Access denied for user &#39;root&#39;@&#39;localhost&#39; (using password: YES)

With `mySQL -u root -p` I logged into the DB and did

    GRANT ALL PRIVILEGES ON *.* TO &#39;root&#39;@&#39;localhost&#39; IDENTIFIED BY &#39;&lt;PW&gt;&#39;;
    FLUSH ALL PRIVILEGES;

But this did not help. Have you got any idea?
I did not find the answer for the similar questions.

Access denied for user &#39;root&#39;@&#39;localhost&#39; (using password: YES) after new installation on Ubuntu

I don&#39;t understand why

    SELECT UUID();
    
Returns something like:

    3f06af63-a93c-11e4-9797-00505690773f

But if I insert it into a binary(16) field (the UUID() function) with for instance a BEFORE INSERT trigger and run a select, it returns something like:

    0782ef48-a439-11

Note that these two UUIDs are not the same data.

I realize binary and an UUID string doesn&#39;t look identical, but shouldn&#39;t the selected data at least be just as long? Otherwise how can it possibly be equally likely to be unique?

Is it better to store it as char(36)? I just need it to be unique to prevent duplicate inserts. It is never selected or used for joins.

EDIT:

before trigger would be like:

    BEGIN
    
    if NEW.UUID IS NULL THEN
    
    NEW.UUID = UUID();
    
    END IF
    
    END

Inserting and selecting UUIDs as binary(16)

I have a docker container with some processes (uwsgi and celery) running inside. I want to create a celery user and a uwsgi user for these processes as well as a worker group that they will both belong to, in order to assign permissions. 

I tried adding `RUN adduser uwsgi` and `RUN adduser celery` to my Dockerfile, but this is causing problems, since these commands prompt for input (I&#39;ve posted the responses from the build below). 

What is the best way to add users to a Docker container so as to set permissions for workers running in the container?

My Docker image is built from the official Ubuntu14.04 base.

Here is the output from the Dockerfile when the adduser commands are run:

    Adding user `uwsgi&#39; ...
    Adding new group `uwsgi&#39; (1000) ... 
    Adding new user `uwsgi&#39; (1000) with group `uwsgi&#39; ... 
    Creating home directory `/home/uwsgi&#39; ...
    Copying files from `/etc/skel&#39; ... 
    [91mEnter new UNIX password: Retype new UNIX password: [0m 
    [91mpasswd: Authentication token manipulation error
    passwd: password unchanged
    [0m 
    [91mUse of uninitialized value $answer in chop at /usr/sbin/adduser line 563.
    [0m 
    [91mUse of uninitialized value $answer in pattern match (m//) at /usr/sbin/adduser line 564.
    [0m 
    Try again? [y/N] 
    Changing the user information for uwsgi
    Enter the new value, or press ENTER for the default
    	Full Name []: 
    Room Number []: 	Work Phone []: 	Home Phone []: 	Other []: 
    [91mUse of uninitialized value $answer in chop at /usr/sbin/adduser line 589.
    [0m 
    [91mUse of uninitialized value $answer in pattern match (m//) at /usr/sbin/adduser line 590.
    [0m 
    Is the information correct? [Y/n] 
    ---&gt; 258f2f2f13df 
    Removing intermediate container 59948863162a 
    Step 5 : RUN adduser celery 
    ---&gt; Running in be06f1e20f64 
    Adding user `celery&#39; ...
    Adding new group `celery&#39; (1001) ... 
    Adding new user `celery&#39; (1001) with group `celery&#39; ... 
    Creating home directory `/home/celery&#39; ...
    Copying files from `/etc/skel&#39; ... 
    [91mEnter new UNIX password: Retype new UNIX password: [0m 
    [91mpasswd: Authentication token manipulation error
    passwd: password unchanged
    [0m 
    [91mUse of uninitialized value $answer in chop at /usr/sbin/adduser line 563.
    [0m 
    [91mUse of uninitialized value $answer in pattern match (m//) at /usr/sbin/adduser line 564.
    [0m 
    Try again? [y/N] 
    Changing the user information for celery
    Enter the new value, or press ENTER for the default
    	Full Name []: 	Room Number []: 	Work Phone []: 
    Home Phone []: 	Other []: 
    [91mUse of uninitialized value $answer in chop at /usr/sbin/adduser line 589.
    [0m 
    [91mUse of uninitialized value $answer in pattern match (m//) at /usr/sbin/adduser line 590.
    [0m 
    Is the information correct? [Y/n] 


How to add users to Docker container?

I&#39;ve an Ubuntu 14.04 kernel. I was installing my Laravel application in this server. 
After installing, I tried to set the root directory to public. 

    sudo nano /etc/apache2/sites-available/000-default.conf
I have only these options in the file

    &lt;VirtualHost *:80&gt;
            # The ServerName directive sets the request scheme, hostname and port t$
            # the server uses to identify itself. This is used when creating
            # redirection URLs. In the context of virtual hosts, the ServerName
            # specifies what hostname must appear in the request&#39;s Host: header to
            # match this virtual host. For the default virtual host (this file) this
            # value is not decisive as it is used as a last resort host regardless.
            # However, you must set it for any further virtual host explicitly.
            #ServerName www.example.com
    
            ServerAdmin webmaster@localhost
            DocumentRoot /var/www/html/public/
    
            # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
            # error, crit, alert, emerg.
            # It is also possible to configure the loglevel for particular
            # modules, e.g.
            #LogLevel info ssl:warn
    
            ErrorLog ${APACHE_LOG_DIR}/error.log
            CustomLog ${APACHE_LOG_DIR}/access.log combined
    
            # For most configuration files from conf-available/, which are
            # enabled or disabled at a global level, it is possible to
            # include a line for only one particular virtual host. For example the
            # following line enables the CGI configuration for this host only
            # after it has been globally disabled with &quot;a2disconf&quot;.
            #Include conf-available/serve-cgi-bin.conf
    &lt;/VirtualHost&gt;
    
    # vim: syntax=apache ts=4 sw=4 sts=4 sr noet

I&#39;ve changed the Document root to

    DocumentRoot /var/www/html/public/

Now when I tried to access my Laravel App, through `123.xxx.xxx.xxx/` it shows the home page and working well. It gets all the GET variable too. Eg: `123.xxx.xxx.xxx?type=wefwef`

But when I go to other links such as `123.xxx.xxx.xxx/login` it gives me an error

    Not Found
    
    The requested URL /login/ was not found on this server.
    
    Apache/2.4.7 (Ubuntu) Server at 104.236.234.85 Port 80

I have the routes.php working well on localhost. But not on this server. Please help me. 

laravel the requested url was not found on this server

I have to install Android Studio on Ubuntu and I have used [this link][1] to download Android Studio.

Is there any easy way to install Studio on Ubuntu?


  [1]: https://developer.android.com/studio/index.html

How to install Android Studio on Ubuntu?

I&#39;m running a Ubuntu Docker container. I have a Norwegian keyboard and need to use Norwegian characters (&#248;&#230;&#229;).

My Terminal character encoding is set to UTF-8 and I&#39;m connected to my container using SSH. However, I&#39;m unable to type Norwegian characters, nor copy and paste Norwegian characters, nor use CTL+SHIFT+U+00f8.

I tried:

    locale-gen nb_NO.UTF-8

but nothing changed. How do I set the locale and keyboard inside a Docker container?

How to set the locale inside a Debian/Ubuntu Docker container?

I have a development server hosted on Digital Ocean, using Ubuntu 14.04.  I switched my shell to ZSH and decided to go with the **Agnoster** theme.  In order to get `user@hostname` to stop showing, I set the `DEFAULT_USER` in my .zshrc file.

For some reason on the ubuntu server, that&#39;s not working.  The hostname still shows, and will not go away.  I&#39;m doing the exact same thing on my Mac OSX, and it works fine.

Here are some screenshots:

![enter image description here][1]

![enter image description here][2]

Anyone know what&#39;s going on? I even tried `DEFAULT_USER=&quot;$USER@$HOST&quot;` with no luck.

If I go back to the default, **Robby Russell** theme, it works just fine.

![enter image description here][3]


  [1]: http://i.stack.imgur.com/2Jq5U.png
  [2]: http://i.stack.imgur.com/HRgMV.png
  [3]: http://i.stack.imgur.com/Q7ERV.png

Content Type	Original Author	Original Content on Stackoverflow
Question	Green Lei	View Question on Stackoverflow
Solution 1 - Mysql	hd1	View Answer on Stackoverflow
Solution 2 - Mysql	Gerald Schade	View Answer on Stackoverflow
Solution 3 - Mysql	Ryan	View Answer on Stackoverflow
Solution 4 - Mysql	Anmol Mourya	View Answer on Stackoverflow
Solution 5 - Mysql	Jayesh	View Answer on Stackoverflow
Solution 6 - Mysql	krunal patel	View Answer on Stackoverflow
Solution 7 - Mysql	Usman	View Answer on Stackoverflow

How can I check if mysql is installed on ubuntu?

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Example

Solution 2 - Mysql

Solution 3 - Mysql

Solution 4 - Mysql

Solution 5 - Mysql

Solution 6 - Mysql

For debian or other dpkg-based systems, check like this: * dpkg -l mysql-server libmysqlclientdev*

Solution 7 - Mysql

Why is ;; allowed after a local variable declaration, but not after a field declaration?

Hide traceback unless a debug flag is set

Attributions