query operators and modifier
The query operators and modifier are extensions to the MongoDB API.
Query operators
You can use the query operators in all MongoDB functions that accept query operators, for example find() or findOne().- $ifxtext
- The $ifxtext query operator is similar to the MongoDB $text operator, except that it passes the search string as-is to the bts_contains() function.
- When using relational tables, the MongoDB $text and $ifxtext query operators both require a column name, specified by $key, in addition to the $search string.
- The search string can be a word or a phrase as well as optional query term modifiers, operators, and stopwords. You can include field names to search in specific fields. The syntax of the search string in the $ifxtext query operator is the same as the syntax of the search criteria in the bts_contains() function that you include in an SQL query.
- In the following example, a single-character wildcard search is run for the strings
text or
test:
db.collection.find( { "$ifxtext" : { "$search" : "te?t” } } ) - $like
- The $like query operator tests for matching character strings and maps to the SQL LIKE query operator. For more information about the SQL LIKE query operator, see LIKE Operator.
- In the following example, a wildcard search is run for strings that contain
machine:
db.collection.find( { "$like" : "%machine%" )
Query modifier
You can use the query modifier in the MongoDB find() function with the addSpecial function.- $nativeCursor
- The $nativeCursor query modifier holds open a true cursor on the database server during a query. A native cursor requires more wire listener resources because connections and result set objects are tied to a single session, but the cursor guarantees consistent query results. You can control the cursor idle timeout with the cursor.idle.timeout wire listener property. For REST API queries, use the killCursors command to close the cursor.
- In the following example, query results are returned in a
cursor:
db.collection.find().addSpecial("$nativeCursor",1);