mirror of
https://github.com/elastic/elasticsearch.git
synced 2025-06-29 09:54:06 -04:00
a8b2428dd1
* Restructure query-languages docs files for clarity (#124797) In a few previous PR's we restructured the ES|QL docs to make it possible to generate them dynamically. This PR just moves a few files around to make the query languages docs easier to work with, and a little more organized like the ES|QL docs. A bit part of this was setting up redirects to the new locations, so other repo's could correctly link to the elasticsearch docs. * After running tests, we revert a few features * Fix build.gradle and improved some generating code * After running tests * Update x-pack/plugin/esql/build.gradle
105 lines
3.4 KiB
Markdown
105 lines
3.4 KiB
Markdown
---
|
|
mapped_pages:
|
|
- https://www.elastic.co/guide/en/elasticsearch/reference/current/sql-index-patterns.html
|
|
---
|
|
|
|
# Index patterns [sql-index-patterns]
|
|
|
|
Elasticsearch SQL supports two types of patterns for matching multiple indices or tables:
|
|
|
|
|
|
## {{es}} multi-target syntax [sql-index-patterns-multi]
|
|
|
|
The {{es}} notation for enumerating, including or excluding [multi-target syntax](/reference/elasticsearch/rest-apis/api-conventions.md#api-multi-index) is supported *as long* as it is quoted or escaped as a table identifier.
|
|
|
|
For example:
|
|
|
|
```sql
|
|
SHOW TABLES "*,-l*";
|
|
|
|
catalog | name | type | kind
|
|
---------------+---------------+----------+---------------
|
|
javaRestTest |emp |TABLE |INDEX
|
|
javaRestTest |employees |VIEW |ALIAS
|
|
```
|
|
|
|
Notice the pattern is surrounded by double quotes `"`. It enumerated `*` meaning all indices however it excludes (due to `-`) all indices that start with `l`. This notation is very convenient and powerful as it allows both inclusion and exclusion, depending on the target naming convention.
|
|
|
|
The same kind of patterns can also be used to query multiple indices or tables.
|
|
|
|
For example:
|
|
|
|
```sql
|
|
SELECT emp_no FROM "e*p" LIMIT 1;
|
|
|
|
emp_no
|
|
---------------
|
|
10001
|
|
```
|
|
|
|
::::{note}
|
|
There is the restriction that all resolved concrete tables have the exact same mapping.
|
|
::::
|
|
|
|
|
|
[preview] To run a [{{ccs}}](docs-content://solutions/search/cross-cluster-search.md), specify a cluster name using the `<remote_cluster>:<target>` syntax, where `<remote_cluster>` maps to a SQL catalog (cluster) and `<target>` to a table (index or data stream). The `<remote_cluster>` supports wildcards (`*`) and `<target>` can be an index pattern.
|
|
|
|
For example:
|
|
|
|
```sql
|
|
SELECT emp_no FROM "my*cluster:*emp" LIMIT 1;
|
|
|
|
emp_no
|
|
---------------
|
|
10001
|
|
```
|
|
|
|
|
|
## SQL `LIKE` notation [sql-index-patterns-like]
|
|
|
|
The common `LIKE` statement (including escaping if needed) to match a wildcard pattern, based on one `_` or multiple `%` characters.
|
|
|
|
Using `SHOW TABLES` command again:
|
|
|
|
```sql
|
|
SHOW TABLES LIKE 'emp%';
|
|
|
|
catalog | name | type | kind
|
|
---------------+---------------+----------+---------------
|
|
javaRestTest |emp |TABLE |INDEX
|
|
javaRestTest |employees |VIEW |ALIAS
|
|
```
|
|
|
|
The pattern matches all tables that start with `emp`.
|
|
|
|
This command supports *escaping* as well, for example:
|
|
|
|
```sql
|
|
SHOW TABLES LIKE 'emp!%' ESCAPE '!';
|
|
|
|
catalog | name | type | kind
|
|
---------------+---------------+---------------+---------------
|
|
```
|
|
|
|
Notice how now `emp%` does not match any tables because `%`, which means match zero or more characters, has been escaped by `!` and thus becomes an regular char. And since there is no table named `emp%`, an empty table is returned.
|
|
|
|
In a nutshell, the differences between the two type of patterns are:
|
|
|
|
| | | |
|
|
| --- | --- | --- |
|
|
| **Feature** | **Multi index** | **SQL `LIKE`** |
|
|
| Type of quoting | `"` | `'` |
|
|
| Inclusion | Yes | Yes |
|
|
| Exclusion | Yes | No |
|
|
| Enumeration | Yes | No |
|
|
| One char pattern | No | `_` |
|
|
| Multi char pattern | `*` | `%` |
|
|
| Escaping | No | `ESCAPE` |
|
|
|
|
Which one to use, is up to you however try to stick to the same one across your queries for consistency.
|
|
|
|
::::{note}
|
|
As the query type of quoting between the two patterns is fairly similar (`"` vs `'`), Elasticsearch SQL *always* requires the keyword `LIKE` for SQL `LIKE` pattern.
|
|
::::
|
|
|
|
|