Important
Helios features are now enabled during weekly update windows and are no longer directly tied to SingleStore engine releases. Refer to the release notes to view the latest features available in your Helios cluster.
BSON_
On this page
The BSON_ function extracts the string value for the specified key from the BSON data, converts it to a SingleStore string type, and returns the value.
Syntax
BSON_EXTRACT_STRING(<input> [, path_key_1, path_key_2,.., path_key_n])Arguments
-
<input>: A valid BSON document or an expression that evaluates to a valid BSON document. -
<path>: A comma-separated list of dictionary keys or array positions (zero-based index).
Return Type
A string.
Remarks
-
The BSON string types are returned as is.
-
The default collation for this function is
utf8mb4_.bin -
Returns
NULLif:-
The extracted value is an invalid BSON string, a BSON type other than string, or
NULL. -
The specified path does not exist.
-
Examples
Note: The following examples explicitly cast string to BSON for clarity.
The following example extracts a string:
SELECT BSON_EXTRACT_STRING('{"a":{"b":"A valid string"}}':>BSON, 'a', 'b') AS Result;
+----------------+
| Result |
+----------------+
| A valid string |
+----------------+The following examples return NULL because of invalid input types:
SELECT BSON_EXTRACT_STRING('{"a":{"b":{"$numberDecimal":"12.5"}}}':>BSON, 'a', 'b') AS Result;
+--------+
| Result |
+--------+
| NULL |
+--------+SELECT BSON_EXTRACT_STRING('{"a":{"b":{"$date":"2023-03-14T09:48:10.720Z"}}}':>BSON, 'a', 'b') AS Result;
+--------+
| Result |
+--------+
| NULL |
+--------+SELECT BSON_EXTRACT_STRING('{"a":{"b":{"$oid":"641044fd4542e7dc53758df9"}}}':>BSON, 'a', 'b') AS Result;
+--------+
| Result |
+--------+
| NULL |
+--------+Last modified: