本文讲解一下用脚本如何去修改一个数组的值。
我们给此文档新增一个可以有多个值的属性，然后进行脚本操作
4.新增字段
POST /policy_document/policy_document/222/_update
{
"doc": {
"tags":["重要"]
}
}或者用脚本新增
POST policy_document/policy_document/121/_update
{
"script": {
"inline": "ctx._source.address='[XIAN, HENAN, NANJIN, American, Canada]'"
}
}
5.查询出此文档
这个tags字段，他的值是个字符串数组
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 8,
"found": true,
"_source": {
"level": "国家",
"plat_from": 11,
"reference_number": "222new",
"title": "省级文明单位颁发文件111new号",
"from_type": 1,
"id": "111",
"_id_": "111",
"launch_date": 1485878400000,
"launch_department": "国家科技局222new",
"view_time": 5,
"tags": [
"重要"
]
}
}6.先用put去修改
POST /policy_document/policy_document/222/_update
{
"doc": {
"tags":["一般重要"]
}
}返回
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 9,
"result": "updated",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
}
}7.查询出此文档
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 9,
"found": true,
"_source": {
"level": "国家",
"plat_from": 11,
"reference_number": "222new",
"title": "省级文明单位颁发文件111new号",
"from_type": 1,
"id": "111",
"_id_": "111",
"launch_date": 1485878400000,
"launch_department": "国家科技局222new",
"view_time": 5,
"tags": [
"一般重要"
]
}
}发现原来的值被覆盖了，所以，如果这样修改的话，如果想保留原来的值，然后继续往这个数组中添加的话，那我们需要把原来的值也传递过来才行，我们试一下：
8.再次put修改
POST /policy_document/policy_document/222/_update
{
"doc": {
"tags":["重要","一般重要"]
}
}9.查询出此文档
GET /policy_document/policy_document/222{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 10,
"found": true,
"_source": {
"level": "国家",
"plat_from": 11,
"reference_number": "222new",
"title": "省级文明单位颁发文件111new号",
"from_type": 1,
"id": "111",
"_id_": "111",
"launch_date": 1485878400000,
"launch_department": "国家科技局222new",
"view_time": 5,
"tags": [
"重要",
"一般重要"
]
}
}此时的值是符合我们要求的。但是显然，这种方式会有一个弊端：如果这个数组中存的是文件，比如某个文章中添加的附件，这个文章会有很多的附件，而且我们把附件转为了base64字符串或者二进制格式存储的；那么每次使用者在增加一个新附件时，我们还要去某个地方把原来的文件都取出来一下，然后和这个新文件一起拼接过来，对这个字段的值进行整体替换。此时，脚本更新，可以完美的解决这个问题。
10.脚本更新
以下是2.x版本的脚本语法
POST policy_document/policy_document/222/_update
{
"script": "ctx._source.tags.add(params.tag)",
"params":{
"tag":"有点重要"
}
}返回
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 11,
"result": "updated",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
}
}11.查看此文档
发现加了个null进去了
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 11,
"found": true,
"_source": {
"level": "国家",
"plat_from": 11,
"reference_number": "222new",
"title": "省级文明单位颁发文件111new号",
"from_type": 1,
"id": "111",
"_id_": "111",
"launch_date": 1485878400000,
"launch_department": "国家科技局222new",
"view_time": 5,
"tags": [
"重要",
"一般重要",
null
]
}
}12.重新添加
这里要注意，Elasticsearch现在已经有几十个版本了，不同的版本，脚本格式差别还是挺大的，大家可以自己去官网查询对应版本下的脚本格式https://www.elastic.co/guide/en/elasticsearch/reference/5.5/docs-update.html，我这里用的是5.5.0版本，脚本格式如下：
POST policy_document/policy_document/222/_update
{
"script": {
"inline":"ctx._source.tags.add(params.tag)",
"params": {
"tag":"有点重要"
}
}
}返回
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 12,
"result": "updated",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
}
}13.查看此文档
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "222",
"_version": 12,
"found": true,
"_source": {
"level": "国家",
"plat_from": 11,
"reference_number": "222new",
"title": "省级文明单位颁发文件111new号",
"from_type": 1,
"id": "111",
"_id_": "111",
"launch_date": 1485878400000,
"launch_department": "国家科技局222new",
"view_time": 5,
"tags": [
"重要",
"一般重要",
null,
"有点重要"
]
}
}14.脚本添加nested类型如数组时，有个坑，需要注意：
先建一个新文档
PUT policy_document/policy_document/122/_create
{
"title":"测试数组"
}{
"_index": "policy_document",
"_type": "policy_document",
"_id": "122",
"_version": 1,
"found": true,
"_source": {
"title": "测试数组"
}
}添加一个nest类型的字段(错误方式)
POST policy_document/policy_document/122/_update
{
"script": {
"inline": "ctx._source.color='[red,green]'"
}
}结果如下：
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "122",
"_version": 2,
"found": true,
"_source": {
"title": "测试数组",
"color": "[red,green]"
}
}会发现这个color无法添加新元素，因为它不是数组，是一个字符串，正确的添加方式如下：
POST policy_document/policy_document/122/_update
{
"script": {
"inline": "ctx._source.color=['red','green']"
}
}结果如下：
{
"_index": "policy_document",
"_type": "policy_document",
"_id": "122",
"_version": 3,
"found": true,
"_source": {
"title": "测试数组",
"color": [
"red",
"green"
]
}
}