Defining relationship mapping for the CI types to transfer

You can define the relationship between the CI types that you are transferring to BMC CMDB depending on whether the relationship data in your source tables is class-based or stored in an external table.

Defining relationship mapping based on attributes in CI classes

If your relationship data is stored within your source CI tables, you can follow the example in Source data organization at Calbro Services. You would have defined a mapping for the BMC_DiskDrive CI class that contains an attribute called AssociatedComputer. This attribute associates an instance of a disk drive with an instance of a computer. For example, disk 1520 in the Disk Drive table is associated with computer vm2-w4-dev01 in the Computer table. You also would have defined a mapping for the BMC_ComputerSystem CI class that contains an attribute called Name. This attribute defines the name of a computer that you have in inventory. 

Because each disk drive in your company is associated with a computer, you can create a mapping for the BMC_HostedSystemComponents relationship class that associates a particular instance of BMC_DiskDrive with a particular instance of BMC_ComputerSystem. In this case, the AssociatedComputer attribute in the BMC_DiskDrive class and the Name attribute in the BMC_ComputerSystem class contain the data necessary to create the relationship. 

Each relationship class in BMC CMDB defines one CI class as the parent member of the relationship and another CI class as the child member of the relationship. In this case, BMC_ComputerSystem is the source (parent) member and BMC_DiskDrive is the destination (child) member of the BMC_HostedSystemComponents relationship class. For more information about relationship classes, see Relationship classes in the Common Data Model.

To define relationship mapping with CI classes as the source

1. In the Relationship Mappings page, leave the default selection which says that the relationship data is contained within the source columns of the two CIs. 
   Relationship Mapping page of the Integration Job Builder wizard-CI classes as source
   
   
   The source key that you specified for the parent CI (For example, SerialNumber for Computer system) is displayed in the first column.
2. From the child CI column, select the column that contains the information that associates the child CI with the parent CI.
   In the sample Calbro scenario ( Creating a data transfer job), the Computer system Key Column displays SerialNumber (the source key for computer system). From the Disk drive Columns, the Calbro administrator selects AssociatedComputer, which maps a disk drive to appropriate computer system.
3. Click Next.
   The Relationship Mapping page appears.

Defining relationship mapping with an external data store as the source

This method compares attributes between each CI class and the external data store. The instance IDs of these member CIs are stored in the relationship instance as Source.InstanceId and Destination.InstanceId. If no attribute values correspond, no relationship instance is created. 

The following figures present an example of mapping in two stages based on relationship data stored in an external data store.

Stage 1 of creating a data mapping based on relationship data stored in an external data store 


In Stage 1, the Name attribute from the Computer Information table from the external data store is mapped to the Name attribute of the BMC_ComputerSystem class. Instance IDs for individual members of the BMC_ComputerSystem class are generated. The Name attribute from the Disk Drive Information table from the external data store is mapped to the Name attribute in the BMC_DiskDrive class. Instance IDs for individual members of the BMC_DiskDrive class are also generated. In this stage, no relationship is created. 

Stage 2 of creating a data mapping based on relationship data stored in an external data store 



In Stage 2, when the data exchange runs, a match is found between the values of the AssociatedComputer attribute from the Disk Drive Information table and the Name attribute from the BMC_ComputerSystem class. 
When attributes from a data table in an external data store correspond between two CI classes in BMC CMDB, a relationship is created between the two CI classes in BMC CMDB. 
In this example, attributes from the Disk Drive Information table in the external data store correspond to the attributes in the BMC_ComputerSystem and BMC_DiskDrive tables in BMC CMDB. A relationship is thus created between BMC_ComputerSystem and BMC_DiskDrive. This relationship is stored in the BMC_HostedSystemComponents relationship class. 
BMC_ComputerSystem becomes the source class and BMC_DiskDrive becomes the destination class for the relationship mapping. The instance IDs of the member CIs are stored in the BMC_HostedSystemComponents relationship class as Source.InstanceId and Destination.InstanceId for BMC_ComputerSystem and BMC_DiskDrive.

To define relationship mapping with external data store as the source

1. In the Relationship Mappings page, select the button whose label says that the key columns of the CIs are related using columns in an external table. 
   Relationship Mapping page of the Integration Job Builder wizard-external data store as source
   
2. Specify the schema and name of the external table containing the relationship information.
3. For the parent CI, the source key is displayed in the left column. In the Association Table Columns, select the column from the external table that maps to the source key.
4. For the child CI, the source key is displayed in the left column. In the Association Table Columns, select the column from the external table that maps to the source key.
5. Click the Transformation Options tab and specify the delta options.
6. Click Next.
   The Schedule page appears.

Where to go from here

Mapping target attributes to source columns