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[[query-dsl-simple-query-string-query]]
=== Simple Query String Query
A query that uses the SimpleQueryParser to parse its context. Unlike the
regular `query_string` query, the `simple_query_string` query will never
throw an exception, and discards invalid parts of the query. Here is
an example:
[source,js]
--------------------------------------------------
{
"simple_query_string" : {
"query": "\"fried eggs\" +(eggplant | potato) -frittata",
"analyzer": "snowball",
"fields": ["body^5","_all"],
"default_operator": "and"
}
}
--------------------------------------------------
The `simple_query_string` top level parameters include:
[cols="<,<",options="header",]
|=======================================================================
|Parameter |Description
|`query` |The actual query to be parsed. See below for syntax.
|`fields` |The fields to perform the parsed query against. Defaults to the
`index.query.default_field` index settings, which in turn defaults to `_all`.
|`default_operator` |The default operator used if no explicit operator
is specified. For example, with a default operator of `OR`, the query
`capital of Hungary` is translated to `capital OR of OR Hungary`, and
with default operator of `AND`, the same query is translated to
`capital AND of AND Hungary`. The default value is `OR`.
|`analyzer` |The analyzer used to analyze each term of the query when
creating composite queries.
|`flags` |Flags specifying which features of the `simple_query_string` to
enable. Defaults to `ALL`.
|`lowercase_expanded_terms` | Whether terms of prefix and fuzzy queries are to
be automatically lower-cased or not (since they are not analyzed). Defaults to
true.
|=======================================================================
[float]
==== Simple Query String Syntax
The `simple_query_string` supports the following special characters:
* `+` signifies AND operation
* `|` signifies OR operation
* `-` negates a single token
* `"` wraps a number of tokens to signify a phrase for searching
* `*` at the end of a term signifies a prefix query
* `(` and `)` signify precedence
* `~N` after a word signifies edit distance (fuzziness)
* `~N` after a phrase signifies slop amount
In order to search for any of these special characters, they will need to
be escaped with `\`.
[float]
==== Default Field
When not explicitly specifying the field to search on in the query
string syntax, the `index.query.default_field` will be used to derive
which field to search on. It defaults to `_all` field.
So, if `_all` field is disabled, it might make sense to change it to set
a different default field.
[float]
==== Multi Field
The fields parameter can also include pattern based field names,
allowing to automatically expand to the relevant fields (dynamically
introduced fields included). For example:
[source,js]
--------------------------------------------------
{
"simple_query_string" : {
"fields" : ["content", "name.*^5"],
"query" : "foo bar baz"
}
}
--------------------------------------------------
[float]
==== Flags
`simple_query_string` support multiple flags to specify which parsing features
should be enabled. It is specified as a `|`-delimited string with the
`flags` parameter:
[source,js]
--------------------------------------------------
{
"simple_query_string" : {
"query" : "foo | bar & baz*",
"flags" : "OR|AND|PREFIX"
}
}
--------------------------------------------------
The available flags are: `ALL`, `NONE`, `AND`, `OR`, `PREFIX`, `PHRASE`,
`PRECEDENCE`, `ESCAPE`, `WHITESPACE`, `FUZZY`, `NEAR`, and `SLOP`.