2016-11-17ââIn this quickstart, you use Docker to pull and run the SQL Server 2017 container image, mssql-server-linux. Then connect with sqlcmd to create your first database and run queries. In this quickstart, you use Docker to pull and run the SQL Server.
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APPLIES TO: SQL Server (Linux only) Azure SQL Database Azure Synapse Analytics (SQL DW) Parallel Data Warehouse
In this quickstart, you use Docker to pull and run the SQL Server 2017 container image, mssql-server-linux. Then connect with sqlcmd to create your first database and run queries.
Tip
If you want to run SQL Server 2019 containers, see the SQL Server 2019 version of this article.
Note
Starting with SQL Server 2019 CU3, Ubuntu 18.04 is supported.
In this quickstart, you use Docker to pull and run the SQL Server 2019 container image, mssql-server. Then connect with sqlcmd to create your first database and run queries.
Tip
This quickstart creates SQL Server 2019 containers. If you prefer to create SQL Server 2017 containers, see the SQL Server 2017 version of this article.
This image consists of SQL Server running on Linux based on Ubuntu 18.04. It can be used with the Docker Engine 1.8+ on Linux or on Docker for Mac/Windows. This quickstart specifically focuses on using the SQL Server on linux image. The Windows image is not covered, but you can learn more about it on the mssql-server-windows-developer Docker Hub page.
Prerequisites
Pull and run the container image
Before starting the following steps, make sure that you have selected your preferred shell (bash, PowerShell, or cmd) at the top of this article.
The
-h (host name) parameter is also useful, but it is not used in this tutorial for simplicity. This changes the internal name of the container to a custom value. This is the name you'll see returned in the following Transact-SQL query:
Setting
-h and --name to the same value is a good way to easily identify the target container.
Pull and run the container image
Before starting the following steps, make sure that you have selected your preferred shell (bash, PowerShell, or cmd) at the top of this article.
The
-h (host name) parameter is also useful, but it is not used in this tutorial for simplicity. This changes the internal name of the container to a custom value. This is the name you'll see returned in the following Transact-SQL query:
Setting
-h and --name to the same value is a good way to easily identify the target container.
Change the SA password
The SA account is a system administrator on the SQL Server instance that gets created during setup. After creating your SQL Server container, the
SA_PASSWORD environment variable you specified is discoverable by running echo $SA_PASSWORD in the container. For security purposes, change your SA password.
Connect to SQL Server
The following steps use the SQL Server command-line tool, sqlcmd, inside the container to connect to SQL Server.
Create and query data
The following sections walk you through using sqlcmd and Transact-SQL to create a new database, add data, and run a simple query.
Create a new database
The following steps create a new database named
TestDB .
Microsoft Au Daemon What Is This
Insert data
Next create a new table,
Inventory , and insert two new rows.
Select data
Now, run a query to return data from the
Inventory table.
Exit the sqlcmd command prompt
Connect from outside the container
You can also connect to the SQL Server instance on your Docker machine from any external Linux, Windows, or macOS tool that supports SQL connections.
The following steps use sqlcmd outside of your container to connect to SQL Server running in the container. These steps assume that you already have the SQL Server command-line tools installed outside of your container. The same principles apply when using other tools, but the process of connecting is unique to each tool.
Other common tools to connect to SQL Server include:
Remove your container
If you want to remove the SQL Server container used in this tutorial, run the following commands:
Warning
Stopping and removing a container permanently deletes any SQL Server data in the container. If you need to preserve your data, create and copy a backup file out of the container or use a container data persistence technique.
Docker demo
After you have tried using the SQL Server container image for Docker, you might want to know how Docker is used to improve development and testing. The following video shows how Docker can be used in a continuous integration and deployment scenario.
Next steps
For a tutorial on how to restore database backup files into a container, see Restore a SQL Server database in a Linux Docker container. To explore other scenarios, such as running multiple containers, data persistence, and troubleshooting, see Configure SQL Server container images on Docker.
Also, check out the mssql-docker GitHub repository for resources, feedback, and known issues.
Components of some Linuxdesktop environments that are daemons include D-Bus, NetworkManager (here called unetwork), PulseAudio (usound), and Avahi.
In multitasking computer operating systems, a daemon (/ËdiËmÉn/ or /ËdeɪmÉn/)[1] is a computer program that runs as a background process, rather than being under the direct control of an interactive user. Traditionally, the process names of a daemon end with the letter d, for clarification that the process is in fact a daemon, and for differentiation between a daemon and a normal computer program. For example, syslogd is a daemon that implements system logging facility, and sshd is a daemon that serves incoming SSH connections.
In a Unix environment, the parent process of a daemon is often, but not always, the init process. A daemon is usually either created by a process forking a child process and then immediately exiting, thus causing init to adopt the child process, or by the init process directly launching the daemon. In addition, a daemon launched by forking and exiting typically must perform other operations, such as dissociating the process from any controlling terminal (tty). Such procedures are often implemented in various convenience routines such as daemon(3) in Unix.
Systems often start daemons at boot time which will respond to network requests, hardware activity, or other programs by performing some task. Daemons such as cron may also perform defined tasks at scheduled times.
Terminology[edit]
The term was coined by the programmers at MIT's Project MAC. They took the name from Maxwell's demon, an imaginary being from a thought experiment that constantly works in the background, sorting molecules.[2]Unix systems inherited this terminology. Maxwell's demon is consistent with Greek mythology's interpretation of a daemon as a supernatural being working in the background, with no particular bias towards good or evil. However, BSD and some of its derivatives have adopted a Christian demon as their mascot rather than a Greek daemon.[citation needed]
The word daemon is an alternative spelling of demon,[3] and is pronounced /ËdiËmÉn/DEE-mÉn. In the context of computer software, the original pronunciation /ËdiËmÉn/ has drifted to /ËdeɪmÉn/DAY-mÉn for some speakers.[1]
Alternate terms for daemon are service (used in Windows, from Windows NT onwards â and later also in Linux), started task (IBM z/OS),[4] and ghost job (XDS UTS).
After the term was adopted for computer use, it was rationalized as a 'backronym' for Disk And Execution MONitor.[5]
Daemons which connect to a computer network are examples of network services.
Implementations[edit]Unix-like systems[edit]
In a strictly technical sense, a Unix-like system process is a daemon when its parent process terminates and the daemon is assigned the init process (process number 1) as its parent process and has no controlling terminal. However, more generally, a daemon may be any background process, whether a child of the init process or not.
On a Unix-like system, the common method for a process to become a daemon, when the process is started from the command line or from a startup script such as an init script or a SystemStarter script, involves:
If the process is started by a super-server daemon, such as inetd, launchd, or systemd, the super-server daemon will perform those functions for the process,[6][7][8] except for old-style daemons not converted to run under systemd and specified as Type=forking[8] and 'multi-threaded' datagram servers under inetd.[6]
MS-DOS[edit]
In the Microsoft DOS environment, daemon-like programs were implemented as terminate and stay resident (TSR) software.
Windows NT[edit]
On Microsoft Windows NT systems, programs called Windows services perform the functions of daemons. They run as processes, usually do not interact with the monitor, keyboard, and mouse, and may be launched by the operating system at boot time. In Windows 2000 and later versions, Windows services are configured and manually started and stopped using the Control Panel, a dedicated control/configuration program, the Service Controller component of the Service Control Manager (sc command), the net start and net stop commands or the PowerShell scripting system.
However, any Windows application can perform the role of a daemon, not just a service, and some Windows daemons have the option of running as a normal process.
What Is Microsoft Au Daemon In Startup Mac OsClassic Mac OS and macOS[edit]
On the classic Mac OS, optional features and services were provided by files loaded at startup time that patched the operating system; these were known as system extensions and control panels. Later versions of classic Mac OS augmented these with fully fledged faceless background applications: regular applications that ran in the background. To the user, these were still described as regular system extensions.
macOS, which is a Unix system, uses daemons. Note that macOS uses the term 'services' to designate software that performs functions selected from the Services menu, rather than using that term for daemons as Windows does.
Etymology[edit]
According to Fernando J. Corbató, who worked on Project MAC in 1963, his team was the first to use the term daemon, inspired by Maxwell's demon, an imaginary agent in physics and thermodynamics that helped to sort molecules, stating, 'We fancifully began to use the word daemon to describe background processes which worked tirelessly to perform system chores'.[9]
In the general sense, daemon is an older form of the word 'demon', from the Greek δαίμÏν. In the Unix System Administration HandbookEvi Nemeth states the following about daemons:[10]
Many people equate the word 'daemon' with the word 'demon', implying some kind of satanic connection between UNIX and the underworld. This is an egregious misunderstanding. 'Daemon' is actually a much older form of 'demon'; daemons have no particular bias towards good or evil, but rather serve to help define a person's character or personality. The ancient Greeks' concept of a 'personal daemon' was similar to the modern concept of a 'guardian angel'âeudaemonia is the state of being helped or protected by a kindly spirit. As a rule, UNIX systems seem to be infested with both daemons and demons.
A further characterization of the mythological symbolism is that a daemon is something which is not visible yet is always present and working its will. In the Theages, attributed to Plato, Socrates describes his own personal daemon to be something like the modern concept of a moral conscience: 'The favour of the gods has given me a marvelous gift, which has never left me since my childhood. It is a voice which, when it makes itself heard, deters me from what I am about to do and never urges me on'.[citation needed]
See also[edit]
References[edit]
External links[edit]
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Daemon_(computing)&oldid=945901204'
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