mirror of
https://github.com/honeymoose/OpenSearch.git
synced 2025-02-06 04:58:50 +00:00
a8a2a83d45
Previously, parsing an arithmetic expression with `*` and no spaces, e.g.: `2*i` threw a parsing exception as the grammar rule for tableIdentifier was clashing with the rule for arithmetic operator `*`. This issue comes already in the lexer and the left part of the expression (in our example `2*`) was recognised as a TABLE_IDENTIFIER token. The solution adopted is to allow the `*` wildcard in the table name only if it's surrounded with double quotes, e.g.: `"my*index"` Closes: #33957
82 lines
2.5 KiB
Plaintext
82 lines
2.5 KiB
Plaintext
[role="xpack"]
|
|
[testenv="basic"]
|
|
[[sql-index-patterns]]
|
|
== Index patterns
|
|
|
|
{es-sql} supports two types of patterns for matching multiple indices or tables:
|
|
|
|
* {es} multi-index
|
|
|
|
The {es} notation for enumerating, including or excluding <<multi-index,multi index syntax>>
|
|
is supported _as long_ as it is quoted or escaped as a table identifier.
|
|
|
|
For example:
|
|
|
|
["source","sql",subs="attributes,callouts,macros"]
|
|
----
|
|
include-tagged::{sql-specs}/docs.csv-spec[showTablesEsMultiIndex]
|
|
----
|
|
|
|
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:
|
|
|
|
["source","sql",subs="attributes,callouts,macros"]
|
|
----
|
|
include-tagged::{sql-specs}/docs.csv-spec[fromTablePatternQuoted]
|
|
----
|
|
|
|
NOTE: There is the restriction that all resolved concrete tables have the exact same mapping.
|
|
|
|
* SQL `LIKE` notation
|
|
|
|
The common `LIKE` statement (including escaping if needed) to match a wildcard pattern, based on one `_`
|
|
or multiple `%` characters.
|
|
|
|
Using `SHOW TABLES` command again:
|
|
|
|
["source","sql",subs="attributes,callouts,macros"]
|
|
----
|
|
include-tagged::{sql-specs}/docs.csv-spec[showTablesLikeWildcard]
|
|
----
|
|
|
|
The pattern matches all tables that start with `emp`.
|
|
|
|
This command supports _escaping_ as well, for example:
|
|
|
|
["source","sql",subs="attributes,callouts,macros"]
|
|
----
|
|
include-tagged::{sql-specs}/docs.csv-spec[showTablesLikeEscape]
|
|
----
|
|
|
|
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:
|
|
|
|
[cols="^h,^,^",options="header"]
|
|
|===
|
|
| 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 `'`), {es-sql} _always_
|
|
requires the keyword `LIKE` for SQL `LIKE` pattern.
|
|
|