Implement CommandBehavior.SchemaOnly

[jacentino]

SchemaOnly command execution mode would be useful in some runtime code generation scenarios. It allows to discover query result structure without real execution.
I used this mode to implement microORM for F#. Thanks to SchemaOnly-based code generation data access code is almost as maintainable as it was statically typed, even if queries are simple strings.

[bgrainger]

This was implemented in #723.

Is there something wrong with the current implementation?

[bgrainger]

Duplicate of #723

[jacentino]

When I executed following command in SchemaOnly mode: insert into blog (name, title, description, owner, createdAt, modifiedAt, modifiedBy) values ( @name, @title, @description, @owner, @createdat, @modifiedAt, @modifiedBy); select last_insert_id() The insert part was executed and a new record was added. That's why I thought it was not implemented at all. Actually, the current implementation is enough for me. wt., 31 sty 2023 o 15:33 Bradley Grainger ***@***.***> napisał(a):

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Closed #1281 <#1281> as not planned. — Reply to this email directly, view it on GitHub <#1281 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA25GMOM54BDMWJTAZPLEOTWVEPE7ANCNFSM6AAAAAAULWEACY> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[bgrainger]

I think CommandBehavior.SchemaOnly is only well-defined for a SELECT query, i.e., something that returns a result set. Using it with other DML or DDL commands is not well-defined.

[jacentino]

Indeed.
System.Data..SqlClient doesn't execute command even if it has no result, e.g.:

insert into blog (name, title, description, owner, createdAt, modifiedAt, modifiedBy)
values ( @name, @title, @description, @owner, @createdat, @modifiedAt, @modifiedBy)

The same query is executed by NpgSql, OracleClient and MySql.Data and a new row is created.
But if we add select returning id, none of them produces side effects.