BSON_UNWIND

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.

Syntax

BSON_UNWIND(<input>)

Argument

<input>: A valid BSON type or array, or an expression that evaluates to a valid BSON type or array.

Return Type

A PSQL array.

Remarks

If the input is a valid non-empty BSON array, a PSQL array is returned.
If the input is a BSON type other than the array, it is mapped to the PSQL array as a single element.
BSON_UNWIND() returns NULL if the input is a SQL NULL, BSON NULL, BSON undefined, or an empty BSON array.

Examples

Note: The following examples explicitly cast string to BSON for clarity. Similarly, the output is cast to JSON. The TABLE() command is used to convert the PSQL array to a set of rows.

The following example adds the BSON input as a single element in the array because the input is not a BSON array.

SQL

SELECT table_col:>JSON AS Result
FROM TABLE(BSON_UNWIND('{"field1":"string value","field2":[12,3,1331,"arr"],"field3":true,"field4":null}':>BSON));

+----------------------------------------------------------------------------------+
| Result                                                                           |
+----------------------------------------------------------------------------------+
| {"field1":"string value","field2":[12,3,1331,"arr"],"field3":true,"field4":null} |
+----------------------------------------------------------------------------------+

The following example converts a BSON array to a PSQL array and returns the result as a set of rows, where each row represents an element in the array.

SQL

SELECT table_col:>JSON AS Result FROM TABLE(BSON_UNWIND('[1,true,null,"a string",2,3,4,5,{"a":"abc","b":[]},{}]':>BSON));

+--------------------+
| Result             |
+--------------------+
| 1                  |
| true               |
| null               |
| "a string"         |
| 2                  |
| 3                  |
| 4                  |
| 5                  |
| {"a":"abc","b":[]} |
| {}                 |
+--------------------+