Relationship query in apex

Salesforce | How to perform inner query in SOQL (Salesforce Object Query Language)? - Forcetalks

relationship query in apex

This is Salesforce Object Query Language designed to work with SFDC Database. For example, Invoice object has relationship with the Customer object and. how to query parent records? Here is an example to query the name of the parent account for a specific (child) opportunity by specifying account relationship. How to set schema for generating the parent-to-child relationship query. Salesforce. author: Talend Documentation Team; EnrichVersion: ; EnrichProdName.

This can be an anti-pattern for situations with high data volume in the parent or child object, when query performance will be a huge concern and heap size could become an issue.

Relationship Query in Apex - Salesforce

Adding selective filters on the parent object, adding filters on the child object, and reducing the number of columns queried will help obviate these issues. While parent-child queries can only descend one level of relationship in the object hierarchy, Apex post-processing can gather child object Ids and re-query to descend additional plies.

This query format takes advantage of the fact that the subquery is treated as returning a typed Id value, not an sObject instance. When we present it as a subquery, no intermediate steps or type conversion are required; the Ids are used directly. Salesforce does require that they be Ids of the correct type of object, however.

In particular, note that you can only use two IN semi-joins or anti-joins in a single query.

relationship query in apex

The semi-join and anti-join can be used to filter Object A based upon Object B using any shared reference field, including reference fields on the two objects that both point to some other Object C. See the Salesforce documentation linked above for in-depth discussion of more use cases. Salesforce only allows one level of semi-join or anti-join, so we perform a sort of synthetic join in Apex of two separately expressed SOQL queries.

For example, we can cover case 5 in a fashion like this: Child Aggregate Query The child aggregate query is suitable for locating and ordering parent records based on a non-zero count of child records, optionally matching the child records against some criterion.

Everyday Salesforce Patterns: Filtering Parent Objects By Child Objects | David Reed

With Spring 10 Saleforce. They allow you to perform joins on multiple objects and traverse the relationship chain to find and return objects.

relationship query in apex

Relationships are available for standard and custom objects in Salesforce. However, their syntax is slightly different. The classic relationship example is accounts and contacts. An account parent can have multiple contacts children. Child-to-Parent Relationship This type of query returns child objects contact containing parent account information: For child-to-parent relationships with custom objects the syntax is slightly different but the results are essentially the same.

This will be explained shortly in the parent-to-child section below. For each relationship you can specify up to 5 levels. This makes for some really cool queries that let you reach way up the relationship chain to fetch data.

How to perform inner query in SOQL (Salesforce Object Query Language)?

For instance you can write a query like this which spans only 4 levels. Parent-to-Child Relationships These types of queries are almost always one-to-many.

relationship query in apex

You specify the relationship using a subquery, where the initial member of the FROM clause is the subquery is related to the initial member of the outer query FROM clause. Here's where the relationship comes into affect.

With standard objects you use the plural name of the object in the subquery. Here's how you would find the name of the relationship using Eclipse: