JSON type parameters status (and JSON feature in general)

[MaceWindu]

I wonder what is the current status for parameters with SqlDbType.Json set.

I've tested both Azure SQL Db (highest available compat level 170) and Azure SQL Managed Instance (with Always-up-to-date update policy) and see following behavior:

Parameter \ Database	Azure SQL DB	Azure Managed Instance
string	✔️	✔️
string + SqlDbType.Json	❌The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. Parameter 3 ("@p1"): JSON data type is not supported in TDS on the server side.	❌RPC was aborted without execution. The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. The RPC name is invalid.
SqlJson	❌The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. Parameter 3 ("@p1"): JSON data type is not supported in TDS on the server side.	❌RPC was aborted without execution. The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. The RPC name is invalid.
SqlJson + SqlDbType.Json	❌The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. Parameter 3 ("@p1"): JSON data type is not supported in TDS on the server side.	❌RPC was aborted without execution. The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. The RPC name is invalid.
JsonDocument	❌No mapping exists from object type System.Text.Json.JsonDocument to a known managed provider native type.	❌Failed to convert parameter value from a JsonDocument to a String.
JsonDocument + SqlDbType.Json	❌Failed to convert parameter value from a JsonDocument to a String.	❌No mapping exists from object type System.Text.Json.JsonDocument to a known managed provider native type.

Looks like the only way to pass JSON to server is to use literal or string-typed parameter. type 35 (SqlJson) is not handled by server and JsonDocument despite different code pathes on client - fails on both.

Also looking at #2622 I observe that nor GetFieldValue<byte[]> nor GetStream APIs supported. Would be nice to have a document that describes actual funtionality for new type:

• how to write json value to database using parameters and bulk copy: supported types and required configuration
• how to read value from data reader: supported types and APIs

[MaceWindu]

Looks like discussion in #2665 contains some details on lack of JsonDocument support and Stream support

[mdaigle]

Hi @MaceWindu, we'll discuss internally and get back to you with the documentation plan as JSON rolls out. Thanks!