ElasticSearch修改索引字段类型

ES不提供修改索引字段类型的操作，只能新建索引再将数据同步过去。

1. 原索引

   PUT old_index
   {
     "mappings": {
       "_doc": {
         "properties": {
           "create_date": {
             "type": "data",
             "format": "yyy-MM-dd ||yyyy/MM/dd"
           }
         }
       }
     }
   }
   

2. 新索引

   PUT new_index
   {
     "mappings": {
       "_doc": {
         "properties": {
           "create_date": {
             "type": "text"
           }
         }
       }
     }
   }
   

3. 同步数据

   POST _reindex
   {
     "source": {
       "index": "old_index"
     },
     "dest": {
       "index": "new_index"
     }
   }
   

4. 查询索引

   GET new_index/_search
   

5. 删除原索引

   DELETE old_index
   

6. 设置别名

   POST /_aliases
   {
     "actions": [
       {
         "add": {
           "index": "new_index",
           "alias": "old_index"
         }
       }
     ]
   }