In Elasticsearch use and deepening, we often encounter a variety of problems;
Here, the record Elasticsearch field is blank records check;
1. Query empty field
When we query a field is empty of data in mysql:
select eid,ent_name from ent_search where enttype_code is NULL;
In elasticsearch, we use the api is exists, this query is: query this field is empty or not this field:
GET ent_search/_search
{
"_source": ["eid","ent_name"],
"query": {
"bool": {
"must_not": {
"exists": {
"field": "enttype_code"
}
}
}
}}
2. Query is not an empty field
When we query a field is not empty of data in mysql:
select eid,ent_name from ent_search where enttype_code is NOT NULL;
In elasticsearch, we use the api is exists, this query is:
GET ent_search/_search
{
"_source": ["eid","ent_name","enttype_code"],
"query": {
"constant_score": {
"filter": {
"exists": {
"field": "enttype_code"
}
}
}
}}
### Query Examples
sql_example： select msg,level from jsonlog3-2019.06.26 where msg is NULL; es_explain: GET /jsonlog3-2019.06.26/_search { "_source": ["msg","level"], "query": { "bool": { "must": [ {"bool": {"must_not": [ {"exists": {"field": "msg"}} ]}} ] } }} sql_example： select msg,level from jsonlog3-2019.06.26 where msg is not NULL; es_explain: GET /jsonlog3-2019.06.26/_search { "_source": ["msg","level"], "query": { "bool": { "must": [ {"bool": {"must": [ {"exists": {"field": "msg"}} ]}} ] } }} OR GET /qdtech-jsonlog3-2019.06.26/_search { "_source": ["msg","level"], "query": { "constant_score": { "filter": { "exists": { "field": "msg" } } } } } NOTE: es in the field does not exist and a null field is the same concept;