apex - How to query child to parent - Salesforce Stack Exchange
Name: Developer-/Admin-defined internal field name in custom objects. Now let's see some SOQL for parent-child relationship. 1). SOQL for. Child to Parent scenario is: PField -parent field CField-Child field RField Account is the standard relation lookup field name defined by sfdc. OR lookup) and we need to fetch all child records using SOQL. First one is for Account(Parent) – Contact (Child) relationship. for account and contacts relationship(already defined by salesforce), the query will be like.
Click on next after selecting another object. Enter field name, description, sharing setting, reparenting options and click on next.
Establish field-level security, add the reference field to page layout, add custom-related lists and click on save.
Apex - SOQL
We can't create a Master-detail relationship on existing records. To do that, we have to create a lookup relationship for that record and then convert it into master detail. To convert a lookup relationship to a master detail the existing record should consist of valid lookup field values.
You can build many to many relationships using two master detail relationships in an object, and it is called as Junction object. Standard objects can't be on a detail side of a master detail relationship. Access to detail is determined by the access given for master.
Only up to two master detail relationships are allowed for an object. You can have only Upto three levels of custom detail levels. We can't create a Master-detail relationship when the custom object already contains data. Each object is allowed to have one or two masters or up to 8 details.
After converting a lookup field into Master-detail relationship, test your custom reports, whether they are usable or not.
That is, the two linked objects in the detail-subdetail1, or subdetail1-subdetail2 relationship have the same conversion limits as the master-detail relationship. Roll-up summary fields work as in two-object master-detail relationships. You can use multilevel master-detail relationships in custom report types.
Relationship Query in Apex – Salesforce
Custom report types created for multilevel master-detail relationships count towards the organizations custom report type limit and no reports are generated if this limit is exceeded.
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. Undeleting a detail record restores it, and undeleting a master record also undeletes related detail and subdetail records. However, if you delete a detail record and later, separately, delete its master record, you cannot undelete the detail record, as it no longer has a master record to relate to.
To delete this object, manually delete junction object records until the count is fewer than This affects the following for the junction object records: If your organization uses divisions to segment data, the junction object records inherit their division from their associated primary master record.
Similar to the record ownership, this is only relevant if you later delete both master-detail relationships. If you delete the primary master-detail relationship or convert it to a lookup relationship, the secondary master object becomes primary.
Roll-up summary fields that summarize data from the junction object can be created on both master objects. Formula fields and validation rules on the junction object can reference fields on both master objects. Lookup Relationships If the lookup field is optional, you can specify one of three behaviors to occur if the lookup record is deleted: Clearing the field is a good choice when the field does not have to contain a value from the associated lookup record.
However, the lookup object can be either standard or custom. Choose when the lookup field and its associated record are tightly coupled and you want to completely delete related data.
To prevent records from being accidentally deleted, cascade-delete is disabled by default. Cascade-delete and its related options are not available for lookup relationships to business hours, community, lead, price book, product, or user objects. In a chain of lookup relationships, these behaviors work independently on each target field at each level. Say, for example, field A is the target lookup of field B, which in turn is the target lookup of field C.
Once B is deleted, the relationship between A and B no longer exists and C will hold an empty value for the lookup. In a multilevel lookup relationship, these options might conflict.
Relationship Queries in salesforce - SalesforceTutorial
If the parent record in a lookup relationship is deleted, the field history tracking for the child record does not record the deletion. For example, if a parent account is deleted, the Account History related list for the child account does not show the deletion.
Relationships on External Objects Lookup, external lookup, and indirect lookup relationships have some special behaviors and limitations. Only lookup, external lookup, and indirect lookup relationships are available for external objects.