+ Start a Discussion

How to convert lookup to master detail relationship and what will happened if its change?



Can any one send the steps how to
"convert lookup reationship field to master detail realtionship"


You just have to create the look up relationship and pupulate that field in all the records. After that you can convert the look up to master detail. This is because the master detail field is basically mandatory on the child record. So unless you specify values in all the records , you wont be allowed to convert the look up to masterdetail.




You can convert a lookup relationship to a master-detail relationship, but only if the lookup field in all records contains a value.

Converting a relationship from lookup to master-detail or vice versa can cause existing custom reports to become unusable due to the different standard report types available for each type of relationship. We recommend that you test your custom reports immediately after converting the relationship type. If you revert your relationship back to the original type, the reports are restored and become usable again.

Converting relationships from lookup to master-detail, or from master-detail to lookup behaves the same as for two-object master-detail relationships. That is, the two linked objects in the detail-subdetail1, or subdetail1-subdetail2 relationship have the same conversion limits as the master-detail relationship.

You can’t delete a custom object if it is on the master side of a master-detail relationship. If you delete a custom object that is on the detail side of a master-detail relationship, the relationship is converted to a lookup relationship.

The second master-detail relationship you create on your junction object becomes the secondary relationship. If you delete the primary master-detail relationship or convert it to a lookup relationship, the secondary master object becomes primary.

For details please refer: https://help.salesforce.com/apex/HTViewHelpDoc?id=relationships_considerations.htm&language=en_US

Yoganand GadekarYoganand Gadekar
  • You can convert a look up to master detail provided if your existing data look ups contain data for all records,
  • Also you should have "Allow reparenting' check box checked for that field otherwise you will find master detail disabled when you try to change the data tyoe to master detail.


Hit kudos and mark this asnnwer if it helps adn solves yourt prblm.

Mark MoggyMark Moggy

Just one more thing - if you are getting a 'time out' - it could be due to a Filter ..

So [Edit] copy/paste the Filter field values into the Description field [Save],

Then [Edit] and change the field type - tick the 'Allow reparenting' box (thank you Yoganand Gadekar) and [Save]

Then [Edit]  and add back the filter and [Save]

Santhosh MekalaSanthosh Mekala
In below link there is detail and step by step explanation for realtionship convertion,