# Change Mapping of Existing Data
**URL:** https://discuss.elastic.co/t/change-mapping-of-existing-data/31438
**Category:** Elasticsearch
**Created:** [October 1, 2015, 6:17am UTC](https://discuss.elastic.co/t/change-mapping-of-existing-data/31438 "2015-10-01T06:17:44Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@krish0608](https://discuss.elastic.co/u/krish0608)
#### Post date: [October 1, 2015, 6:17am UTC](https://discuss.elastic.co/t/change-mapping-of-existing-data/31438/1 "2015-10-01T06:17:44Z")
I want to change my mapping.What should I do to apply new mapping for existing data?please help me out.
POST /thegame/weapons/1
{
"\_id": 1,
"name": "Longsword",
"category": "Sharp"
}
GET /thegame/weapons/\_mapping
POST /thegame/\_close
PUT /thegame/weapons/\_mapping?ignore\_conflicts=true
{
"weapons": {
"properties": {
"name": {
"type": "long",
},
"category": {
"type": "string"
}
}
}
}
POST /thegame/\_open
GET /thegame/\_mappings
Firstly,i put a docs it create default mapping (name:{type:string}),I want to change my default mapping (name:{type:long}).It showing me Error.
Please help me out.
If I reindex my data through Snapshot then also i am not able to change my mapping.
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [October 1, 2015, 6:20am UTC](https://discuss.elastic.co/t/change-mapping-of-existing-data/31438/2 "2015-10-01T06:20:37Z")
You have you reindex the data into a new index that has the correct mapping.
---
### Author:  [@krish0608](https://discuss.elastic.co/u/krish0608)
#### Post date: [October 1, 2015, 6:22am UTC](https://discuss.elastic.co/t/change-mapping-of-existing-data/31438/3 "2015-10-01T06:22:16Z")
HOw to reindex data..please give me some solution??
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [October 1, 2015, 6:31am UTC](https://discuss.elastic.co/t/change-mapping-of-existing-data/31438/4 "2015-10-01T06:31:01Z")
You can e.g. use Logstash, [es-reindex](https://github.com/geronime/es-reindex), or write a custom script in e.g. Python. This has been discussed in these forums several times before so please consult the archives and come back with more specific questions.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 5, 2017, 11:47pm UTC](https://discuss.elastic.co/t/change-mapping-of-existing-data/31438/6 "2017-07-05T23:47:17Z")