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db_command_tutorial [2015/05/22 11:40]
stephdl
db_command_tutorial [2019/06/05 21:48]
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-===== Database variables ===== 
  
-NethServer comes with the most used parameters set as variables in its internal configuration databases. These variables are used to store values to be used in the final configuration files. Please, read the [[http://​docs.nethserver.org/​projects/​nethserver-devel/​en/​latest/​databases.html|Database howto]], the [[http://​docs.nethserver.org/​projects/​nethserver-devel/​en/​latest/​templates.html|template howto]] and the [[http://​docs.nethserver.org/​projects/​nethserver-devel/​en/​latest/​events.html#​signalling-events|event howto]] to understand the template and database process. 
- 
-These variables are useful to configure your system more easily, as you do not need to modify configuration files directly for most common cases. It also makes it possible to administer the server through its server-manager as the database variables are used to set and change configuration parameters. ​ After editing, the configuration files must be regenerated and affected services need to be restarted. 
- 
-For example, suppose you need to increase "​memory-limit"​ in php. 
- 
-You would simply execute these commands at the server console: 
- 
-  db configuration setprop php MemoryLimit 64 
-  signal-event nethserver-php-save 
- 
-The first line changes the value for the memory limit of PHP, the second line regenerates the configuration file and the last line will reload Apache (and subsequently also PHP as this is configured as a module of Apache). 
- 
-<WRAP center round tip 60%> 
-Database parameters are case sensitive so take great care when typing at the server shell because no error messages are given should you make a typo. 
-</​WRAP>​ 
- 
- 
-The database system is based on a flat file system, but you should never edit them directly. Instead you should use the db command. More details on using the database system can be found in the [[http://​docs.nethserver.org/​projects/​nethserver-devel/​en/​latest/​index.html|Developer Manual]] 
- 
-=====Auto completion===== 
- 
-Like in every Linux shell you can use the TAB key when you use the command line to auto complete or propose all available answers 
- 
-=====Usage===== 
-<WRAP center round tip 60%> 
-Use of '​config'​ is a shorthand version for 'db configuration'​ and therefore only works with the configuration database 
-</​WRAP>​ 
- 
-====show all available databases==== 
-To show a list of existing databases do 
-  ls -al /​var/​lib/​nethserver/​db/​ 
- 
-To show the keys for the two main databases do: 
-  db configuration show |less 
-That can be abbreviated to 
-  config show |less 
- 
-  db accounts show |less 
- 
-Note after using the |less switch, press Enter to scroll down a line at a time, or press Space to scroll down a page at a time. '​q'​ to quit. 
-====Create a  key in a database==== 
-the generic command is : 
-  db dbfile set key type [prop1 val1] [prop2 val2] ... 
- 
-  dbfile : choose the database in /​var/​lib/​nethserver/​db/​ 
-  key : the name of key 
-  type : generally '​service'​ or '​configuration'​ but it can be other things as webbapps or url or ... 
-  
-If you want to create a keys called '​plop'​ in the configuration database with a type as '​configuration you can do like this 
- 
-  db configuration set plop configuration Name wordpress PublicAccess private status enabled DbName wordpress DbUser wordpress WpLang en 
- 
-you can see the result 
- 
-  config show plop 
-or  
-  db configuration show plop 
- 
-  plop=configuration 
-    DbName=wordpress 
-    DbUser=wordpress 
-    Name=wordpress 
-    PublicAccess=private 
-    WpLang=en 
-    status=enabled 
- 
-====Change values of properties==== 
-The generic command line is  
-  db dbfile setprop key prop1 val1 [prop2 val2] [prop3 val3] ... 
- 
- 
-  dbfile : choose the database in /​var/​lib/​nethserver/​db/​ 
-  key : the name of key 
- 
-Then if you want to modify some values of our example above 
-  db configuration setprop plop PublicAccess public WpLang fr 
-or 
-  config setprop plop PublicAccess public WpLang fr 
- 
-We want to verify 
-  config show plop  
-or 
-  db configuration show plop 
- 
-  plop=configuration 
-    DbName=wordpress 
-    DbUser=wordpress 
-    Name=wordpress 
-    PublicAccess=public ​ <​----------Here 
-    WpLang=fr ​           <​----------Here 
-    status=enabled 
- 
-====Create a property under a key==== 
- 
-Same as above, really not difficult 
- 
-  db configuration setprop plop PlopTheWorld YES              
-or 
-  config setprop plop PlopTheWorld YES              
- 
-and to display modification 
- 
-  db configuration show plop 
-or 
-  config show plop 
- 
-  plop=configuration 
-    DbName=wordpress 
-    DbUser=wordpress 
-    Name=wordpress 
-    PlopTheWorld=YES ​   <​----------Here 
-    PublicAccess=public 
-    WpLang=fr 
-    status=enabled 
- 
-==== Setting db variables to default values ==== 
-<WRAP center round tip 60%> 
-Use of '​config'​ is a shorthand version for 'db configuration'​ and therefore only works with the configuration database 
-</​WRAP>​ 
- 
- 
-Any db variable that has a default value can be reset to the default by deleting the variable entirely, then re-initializing the default database values as follows: 
- ​config delprop <key> <​prop>​ 
- /​etc/​e-smith/​events/​actions/​initialize-default-databases 
- 
-for example 
-  db configuration delprop plop WPlang 
-  /​etc/​e-smith/​events/​actions/​initialize-default-databases 
-or 
-  config delprop plop WpLang 
-  /​etc/​e-smith/​events/​actions/​initialize-default-databases 
- 
-==== Delete a property value ==== 
-To delete the property 
-  db dbfile delprop <key> <​prop>​ 
-for example 
-  db configuration delprop plop WpLang 
-or 
-  config delprop plop WpLang 
- 
-==== Delete a Key ==== 
-To delete the Key 
-  db dbfile delete <key> 
-for example 
-  db configuration delete plop 
-or 
-  config delete plop 
- 
-==== Reset a property to an empty value ==== 
-To reset to an empty value 
- db dbfile setprop <key> <​prop>​ <​nowiki>''</​nowiki>​ 
- 
-for example 
-  db configuration setprop plop WpLang <​nowiki>''</​nowiki>​ 
-or 
-  config setprop plop WpLang <​nowiki>''</​nowiki>​ 
- 
-<WRAP center round tip 60%> 
-Database parameters are case sensitive so take great care when typing at the server shell because no error messages are given should you make a mistake. 
-</​WRAP>​ 
- 
- 
-{{tag> neth-howto }} 
db_command_tutorial.txt ยท Last modified: 2019/06/05 21:48 (external edit)