singleSelection.merge([object | function, object | function, ...]) → object object.merge([object | function, object | function, ...]) → object sequence.merge([object | function, object | function, ...]) → stream array.merge([object | function, object | function, ...]) → array
Merge two or more objects together to construct a new object with properties from all. When there is a conflict between field names, preference is given to fields in the rightmost object in the argument list. merge also accepts a subquery function that returns an object, which will be used similarly to a map function.
Example: Equip Thor for battle.
r.table('marvel').get('thor').merge(
r.table('equipment').get('hammer'),
r.table('equipment').get('pimento_sandwich')
).run(conn, callback)
Example: Equip every hero for battle, using a subquery function to retrieve their weapons.
r.table('marvel').merge(function (hero) {
return { weapons: r.table('weapons').get(hero('weaponId')) };
}).run(conn, callback)
Example: Use merge to join each blog post with its comments.
Note that the sequence being merged—in this example, the comments—must be coerced from a selection to an array. Without coerceTo the operation will throw an error (“Expected type DATUM but found SELECTION”).
r.table('posts').merge(function (post) {
return {
comments: r.table('comments').getAll(post('id'),
{index: 'postId'}).coerceTo('array')
}
}).run(conn, callback)
Example: Merge can be used recursively to modify object within objects.
r.expr({weapons : {spectacular_graviton_beam : {dmg : 10, cooldown : 20}}}).merge(
{weapons : {spectacular_graviton_beam : {dmg : 10}}}).run(conn, callback)
Example: To replace a nested object with another object you can use the literal keyword.
r.expr({weapons : {spectacular_graviton_beam : {dmg : 10, cooldown : 20}}}).merge(
{weapons : r.literal({repulsor_rays : {dmg : 3, cooldown : 0}})}).run(conn, callback)
Example: Literal can be used to remove keys from an object as well.
r.expr({weapons : {spectacular_graviton_beam : {dmg : 10, cooldown : 20}}}).merge(
{weapons : {spectacular_graviton_beam : r.literal()}}).run(conn, callback)
Couldn't find what you were looking for?
© RethinkDB contributors
Licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.
https://rethinkdb.com/api/javascript/merge/