querying-relationships.md

Querying Relationships

When querying an entity, you may want to restrict the query based on the existence or absence of a related entity. You can do that using the following four methods:

has

Name	Type	Required	Default	Description
relationshipName	String	true		The relationship to check. Can also be a dot-delimited list of nested relationships.
operator	String	false	``	An optional operator to constrain the check. See qb for a list of valid operators.
count	numeric	false	``	An optional count to constrain the check.
negate	boolean	false	false	If true, checks for the the absence of the relationship instead of its existence.

Checks for the existence of a relationship when executing the query.

By default, a has constraint will only return entities that have one or more of the related entity.

getInstance( "User" ).has( "posts" ).get();

An optional operator and count can be added to the call.

getInstance( "User" ).has( "posts", ">", 2 ).get();

Nested relationships can be checked by passing a dot-delimited string of relationships.

getInstance( "User" ).has( "posts.comments" ).get();

doesntHave

Name	Type	Required	Default	Description
relationshipName	String	true		The relationship to check. Can also be a dot-delimited list of nested relationships.
operator	String	false	``	An optional operator to constrain the check. See qb for a list of valid operators.
count	numeric	false	``	An optional count to constrain the check.

Checks for the absence of a relationship when executing the query.

By default, a doesntHave constraint will only return entities that have zero of the related entity.

getInstance( "User" ).doesntHave( "posts" ).get();

An optional operator and count can be added to the call.

getInstance( "User" ).doesntHave( "posts", "<=", 1 ).get();

Nested relationships can be checked by passing a dot-delimited string of relationships.

getInstance( "User" ).doesntHave( "posts.comments" ).get();

whereHas

Name	Type	Required	Default	Description
relationshipName	String	true		The relationship to check. Can also be a dot-delimited list of nested relationships.
closure	Function	true		A closure to constrain the relationship check.
operator	String	false	``	An optional operator to constrain the check. See qb for a list of valid operators.
count	numeric	false	``	An optional count to constrain the check.
negate	boolean	false	false	If true, checks for the the absence of the relationship instead of its existence.

When you need to have more control over the relationship constraint, you can use whereHas. This method operates similarly to has but also accepts a callback to configure the relationship constraint.

The whereHas callback is passed a builder instance configured according to the relationship. You may call any entity or query builder methods on it as usual.

getInstance( "User" )
    .whereHas( "posts", function( q ) {
	      q.where( "body", "like", "%different%" );
    } )
		.get();

When you specify a nested relationship, the builder instance is configured for the last relationship specified.

getInstance( "User" )
    .whereHas( "posts.comments", function( q ) {
	      q.where( "body", "like", "%great%" );
	  } )
	  .get();

An optional operator and count can be added to the call, as well.

getInstance( "User" )
    .whereHas( "posts.comments", function( q ) {
	      q.where( "body", "like", "%great%" );
	  }, ">", 2 )
	  .get();

whereDoesntHave

Name	Type	Required	Default	Description
relationshipName	String	true		The relationship to check. Can also be a dot-delimited list of nested relationships.
closure	Function	true		A closure to constrain the relationship check.
operator	String	false	``	An optional operator to constrain the check. See qb for a list of valid operators.
count	numeric	false	``	An optional count to constrain the check.

The whereDoesntHave callback is passed a builder instance configured according to the relationship. You may call any entity or query builder methods on it as usual.

getInstance( "User" )
    .whereDoesntHave( "posts", function( q ) {
	      q.where( "body", "like", "%different%" );
    } )
		.get();

When you specify a nested relationship, the builder instance is configured for the last relationship specified.

getInstance( "User" )
    .whereDoesntHave( "posts.comments", function( q ) {
	      q.where( "body", "like", "%great%" );
	  } )
	  .get();

An optional operator and count can be added to the call, as well.

getInstance( "User" )
    .whereDoesntHave( "posts.comments", function( q ) {
	      q.where( "body", "like", "%great%" );
	  }, ">", 2 )
	  .get();