[[copy-to]] === `copy_to` The `copy_to` parameter allows you to create custom <<mapping-all-field,`_all`>> fields. In other words, the values of multiple fields can be copied into a group field, which can then be queried as a single field. For instance, the `first_name` and `last_name` fields can be copied to the `full_name` field as follows: [source,js] -------------------------------------------------- PUT /my_index { "mappings": { "my_type": { "properties": { "first_name": { "type": "string", "copy_to": "full_name" <1> }, "last_name": { "type": "string", "copy_to": "full_name" <1> }, "full_name": { "type": "string" } } } } } PUT /my_index/my_type/1 { "first_name": "John", "last_name": "Smith" } GET /my_index/_search { "query": { "match": { "full_name": { <2> "query": "John Smith", "operator": "and" } } } } -------------------------------------------------- // AUTOSENSE <1> The values of the `first_name` and `last_name` fields are copied to the `full_name` field. <2> The `first_name` and `last_name` fields can still be queried for the first name and last name respectively, but the `full_name` field can be queried for both first and last names. Some important points: * It is the field _value_ which is copied, not the terms (which result from the analysis process). * The original <<mapping-source-field,`_source`>> field will not be modified to show the copied values. * The same value can be copied to multiple fields, with `"copy_to": [ "field_1", "field_2" ]`