Refer to the `match` query [documentation]({{site.url}}{{site.baseurl}}/opensearch/query-dsl/full-text/index#match) for parameter descriptions and supported values.
### Example 1: Search the `message` field for the text "this is a test":
```json
GET my_index/_search
{
"query": {
"match": {
"message": "this is a test"
}
}
}
```
*SQL query:*
```sql
SELECT message FROM my_index WHERE match(message, "this is a test")
```
*PPL query:*
```ppl
SOURCE=my_index | WHERE match(message, "this is a test") | FIELDS message
```
### Example 2: Search the `message` field with the `operator` parameter:
```json
GET my_index/_search
{
"query": {
"match": {
"message": {
"query": "this is a test",
"operator": "and"
}
}
}
}
```
*SQL query:*
```sql
SELECT message FROM my_index WHERE match(message, "this is a test", operator='and')
```
*PPL query:*
```ppl
SOURCE=my_index | WHERE match(message, "this is a test", operator='and') | FIELDS message
```
### Example 3: Search the `message` field with the `operator` and `zero_terms_query` parameters:
```json
GET my_index/_search
{
"query": {
"match": {
"message": {
"query": "to be or not to be",
"operator": "and",
"zero_terms_query": "all"
}
}
}
}
```
*SQL query:*
```sql
SELECT message FROM my_index WHERE match(message, "this is a test", operator='and', zero_terms_query='all')
```
*PPL query:*
```sql
SOURCE=my_index | WHERE match(message, "this is a test", operator='and', zero_terms_query='all') | FIELDS message
```
## Multi-match
To search for text in multiple fields, use `MULTI_MATCH` function. This function maps to the `multi_match` query used in search engine, to returns the documents that match a provided text, number, date or boolean value with a given field or fields.
### Syntax
The `MULTI_MATCH` function lets you *boost* certain fields using **^** character. Boosts are multipliers that weigh matches in one field more heavily than matches in other fields. The syntax allows to specify the fields in double quotes, single quotes, surrounded by backticks, or unquoted. Use star ``"*"`` to search all fields. Star symbol should be quoted.
The weight is optional and is specified after the field name. It could be delimited by the `caret` character -- `^` or by whitespace. Please, refer to examples below:
### For example, REST API search for `Dale` in either the `firstname` or `lastname` fields:
```json
GET accounts/_search
{
"query": {
"multi_match": {
"query": "Lane Street",
"fields": [ "address" ],
}
}
}
```
could be called from *SQL* using `multi_match` function
```sql
SELECT firstname, lastname
FROM accounts
WHERE multi_match(['*name'], 'Dale')
```
or `multi_match`*PPL* function
```sql
SOURCE=accounts | WHERE multi_match(['*name'], 'Dale') | fields firstname, lastname
```
| firstname | lastname
:--- | :---
Dale | Adams
## Query string
To split text based on operators, use the `QUERY_STRING` function. The `QUERY_STRING` function supports logical connectives, wildcard, regex, and proximity search.
This function maps to the to the `query_string` query used in search engine, to return the documents that match a provided text, number, date or boolean value with a given field or fields.
### Syntax
The `QUERY_STRING` function has syntax similar to `MATCH_QUERY` and lets you *boost* certain fields using **^** character. Boosts are multipliers that weigh matches in one field more heavily than matches in other fields. The syntax allows to specify the fields in double quotes, single quotes, surrounded by backticks, or unquoted. Use star ``"*"`` to search all fields. Star symbol should be quoted.
The weight is optional and is specified after the field name. It could be delimited by the `caret` character -- `^` or by whitespace. Please, refer to examples below:
Refer to the `query_string` query [documentation]({{site.url}}{{site.baseurl}}/opensearch/query-dsl/full-text/index#query-string) for parameter descriptions and supported values.
Refer to the `match_phrase` query [documentation]({{site.url}}{{site.baseurl}}/opensearch/query-dsl/full-text/index#match-phrase) for parameter descriptions and supported values.
The `simple_query_string` function maps to the `simple_query_string` query in OpenSearch. It returns the documents that match a provided text, number, date or boolean value with a given field or fields.
The **^** lets you *boost* certain fields. Boosts are multipliers that weigh matches in one field more heavily than matches in other fields.
### Syntax
The syntax allows to specify the fields in double quotes, single quotes, surrounded by backticks, or unquoted. Use star ``"*"`` to search all fields. Star symbol should be quoted.
The weight is optional and is specified after the field name. It could be delimited by the `caret` character -- `^` or by whitespace. Please, refer to examples below:
Refer to the `simple_query_string` query [documentation]({{site.url}}{{site.baseurl}}/opensearch/query-dsl/full-text/index#simple-query-string) for parameter descriptions and supported values.
Refer to the `match_phrase_prefix` query [documentation]({{site.url}}{{site.baseurl}}/opensearch/query-dsl/full-text/index#match-phrase-prefix) for parameter descriptions and supported values.
Refer to the `match_bool_prefix` query [documentation]({{site.url}}{{site.baseurl}}/opensearch/query-dsl/full-text/index#match-boolean-prefix) for parameter descriptions and supported values.
