====== Enovia / MQL ======

===== Using conditional selectables =====

Consider we have the following datamodel:
{{ :enovia:enovia_mql_conditionalselectables.png?600 |}}

We want to retrieve the Person object linked with the Project Space object through Member relationship for which the Project Role is set to Contributor (Member relationship attribute).

If we apply the "//**print bus**//" MQL command on the Project Space object and we select the Member relationship (//**print bus 'Project Space' myProject - select from[Member].to.name**//), MQL engine gives us 4 objects (muUser1, myUser2, myUser3 and myUser4).
 
Now, consider the following MQL command : 
<code>print bus 'Project Space' myProject - select from[Member|attribute[Project Role] == Contributor].to.name</code>

The MQL engine gives us only myUser3.

**Rule**:

To perform conditional select when expanding an object, you can include a Where clause criteria in the squarebrackets of select from[ ].to[ ] or to[ ].from[ ] clauses. The relationship or type namepattern is specified first, and then may be followed by the Where clause, the fields delimited by the“|” character.
 
In the previous example, the starting point of the where clause criteria is the expanded relationship. If you want to perform a where clause on the related object (in the example, the Person objects), you can use the following synthax :
<code>print bus 'Project Space' myProject - select from[Member|to.name == Contributor].to.attribute[First Name].value</code>