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en:mervis-db:data-identification [2017/07/21 18:03]
m.chlupac
en:mervis-db:data-identification [2017/07/24 12:32] (current)
m.chlupac [Example]
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 Every variable stored in Mervis DB is identified by set of keys and values. Combination of of keys and values marked with attribute "​IsKey=true"​ defines unique identification of variable (equivalent to **primary key** known from SQL world). Every variable stored in Mervis DB is identified by set of keys and values. Combination of of keys and values marked with attribute "​IsKey=true"​ defines unique identification of variable (equivalent to **primary key** known from SQL world).
  
-===== Keys =====+==== Keys ====
  
 Any string that consists of characters: a-z, A-Z, 0-9, ., _, - can be used as a key. The key must not start with underscore ("​_"​) character and must not be empty. Any string that consists of characters: a-z, A-Z, 0-9, ., _, - can be used as a key. The key must not start with underscore ("​_"​) character and must not be empty.
  
-===== Values ​=====+==== Values ====
  
 Any string that consists of characters: a-z, A-Z, 0-9, ., _, - can be used as a value. Any string that consists of characters: a-z, A-Z, 0-9, ., _, - can be used as a value.
  
  
-==== Example of Variable ​Keys and Values ​====+ 
 +===== Recommended ​Keys ====
 + 
 +It's recommended to use the following structure of keys and values for new projects and Mervis DB clients.
  
 ^Key^Value^IsKey^Description^ ^Key^Value^IsKey^Description^
-SoftPlcRtId ​| "MyRTNumber3025" | **True** |Unique identification of Mervis ​RT defined by user +DataSource ​| "MyDS" | False |Unique identification of the particular data source type. | 
-GUID546 | **True** |Unique identification of Mervis RT variable generated by Mervis ​IDE +| Root | "​MyDsServer1" | **True** |Unique identification of the particular ​Mervis ​DB client. ​
-VariableName ​| "Outside Temperature" | False |Non-unique ​variable ​name defined ​by user in Mervis ​IDE |+Guid"​var546" ​| **True** |Unique identification of variable generated by Mervis ​DB client. ​
 +Level1 ​| "MyLevel1Id" | False | 
 +| Level2 | "​MyLevel2Id"​ | False | | 
 +| Level3 | "​MyLevel3Id"​ | False | | 
 +| Level4 | "​MyLevel4Id"​ | False | | 
 +| Level5 | "​MyLevel5Id"​ | False | | 
 +| Name | "My Variable"​ | False | | 
 +| Unit | "​m3"​ | False | | 
 + 
 + 
 +==== Example ==== 
 +  
 +^Key^Value^IsKey^Description^ 
 +| DataSource | "​SCADASystemXY"​ | False |Unique identification of the particular data source type. | 
 +| Root | "​Server18"​ | **True** |Unique identification of the particular Mervis DB client. | 
 +| Guid| "aaaaa-bbbbb-ccccc-ddddd-eeeee"​ | **True** |Unique identification of variable ​generated ​by Mervis ​DB client. ​| 
 +| Level1 | "​SiteNr500"​ | False | | 
 +| Level2 | "​Building A" | False | | 
 +| Level3 | "Floor 7" | False | | 
 +| Level4 | "Room 17" | False | | 
 +| Level5 | "​SouthEast"​ | False | | 
 +| Name | "​Indoor Temperature"​ | False | | 
 +| Unit | "​C"​ | False | |