Warning
SingleStore 9.0 gives you the opportunity to preview, evaluate, and provide feedback on new and upcoming features prior to their general availability. In the interim, SingleStore 8.9 is recommended for production workloads, which can later be upgraded to SingleStore 9.0.
BSON_
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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: April 2, 2024