Differences

This shows you the differences between two versions of the page.

--- en:mervis-db:data-identification [2017/07/21 18:10]
m.chlupac
+++ en:mervis-db:data-identification [2017/07/24 13:32]
@@ Line 1: / Line 1: @@
-====== Data Identification ======
-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 ====
-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 ====
-Any string that consists of characters: a-z, A-Z, 0-9, ., _, - can be used as a value.
-==== Example of Variable Keys and Values ====
-^Key^Value^IsKey^Description^
-| SoftPlcRtId | "MyRTNumber3025" | **True** |Unique identification of Mervis RT defined by user |
-| GUID| 546 | **True** |Unique identification of Mervis RT variable generated by Mervis IDE |
-| VariableName | "Outside Temperature" | False |Non-unique variable name defined by user in Mervis IDE |
-===== Recommended Keys and Values =====
-It's recommended to use the following structure of keys and values for new projects and Mervis DB clients.
-^Key^Value^IsKey^Description^
-| DataSource | "MyDS" | False |Unique identification of the particular data source |
-| Root | "MyDsServer1" | **True** |Unique identification of the particular Mervis DB client. |
-| 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 |
-| Root | "SCADAServer18" | **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 | |