Left join in FetchXml?

问题

How do i do a left join using FetchXml?

Consider a simple SQL query like the following:

select person.name, address.city from person
left join address on person.addressid = address.addressid

How would something simple like this be done using FetchXml? Currently my FetchXml query looks like the following:

<fetch mapping='logical'>
  <entity name='person'>
    <attribute name='name' />
    <link-entity name='address' from='addressid' to='addressid'>
      <attribute name='city' />
    </link-entity>
  </entity>
</fetch>

回答1:

Update your <link-entity> like so:

<link-entity name='address' from='addressid' to='addressid' link-type='outer'>

来源：https://stackoverflow.com/questions/3218510/left-join-in-fetchxml