hasMany
Usage
A hasMany
relationship is a one-to-many
relationship. For instance, a User
may have multiple Posts
.
The first value passed to hasMany
is a WireBox mapping to the related entity.
Quick determines the foreign key of the relationship based on the entity name and key values. In this case, the Post
entity is assumed to have a userId
foreign key. You can override this by passing a foreign key in as the second argument:
If your parent entity does not use id
as its primary key, or you wish to join the child entity to a different column, you may pass a third argument to the hasMany
method specifying your parent table's custom key.
The inverse of hasMany
is belongsTo
.
Inserting & Updating
There are two ways to add an entity to a hasMany
relationship. Both mirror the insert API for entities.
save
You can call the save
method on the relationship passing in an entity to relate.
This will add the User
entity's id as a foreign key in the Post
and save the Post
to the database.
Note: the
save
method is called on theposts
relationship, not thegetPosts
collection.
saveMany
You can also add many entities in a hasMany
relationship by calling saveMany
. This method takes an array of key values or entities and will associate each of them with the base entity.
create
Use the create
method to create and save a related entity directly through the relationship.
This example will have the same effect as the previous example.
Removing
Removing a hasMany
relationship is handled in two ways: either by using the dissociate
method on the belongsTo
side of the relationship or by deleting the belongsTo
side of the relationship.
Relationship Setter
You can also influence the associated entities by calling "set" & relationshipName
and passing in an array of entities or key values.
After running this code, this user would only have two posts, the posts with ids 2
and 4
. Any other posts would now be disassociated with this user. Likely your database will be guarding against creating these orphan records. Admittedly, this method is not as likely to be used as the others, but it does exist if it solves your use case.
Signature
Name | Type | Required | Default | Description |
---|---|---|---|---|
relationName | string |
| The WireBox mapping for the related entity. | |
foreignKey | String | [String] |
|
| The foreign key on the parent entity. |
localKey | String | [String] |
|
| The local primary key on the parent entity. |
relationMethodName | String |
| The method name called on the entity to produce this relationship. | The method name called to retrieve this relationship. Uses a stack backtrace to determine by default. <b></b> DO NOT PASS A VALUE HERE UNLESS YOU KNOW WHAT YOU ARE DOING. |
Returns a HasMany relationship between this entity and the entity defined by relationName
.