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_ UNWIND
On this page
The BSON_ function converts a BSON document to a PSQL array.
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_returnsUNWIND() NULLif the input is a SQLNULL, BSONNULL, BSONundefined, or an empty BSON array.
Examples
Note: The following examples explicitly cast string to BSON for clarity.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.
SELECT table_col:>JSON AS ResultFROM 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.
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":[]} |
| {} |
+--------------------+Last modified: