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Comment by dotancohen | Hacker News Reader

What about `WHERE foo IN (?,?,?)`. I usually let the language (PHP, Python) handle counting the arguments, but there is no (clean) way to do that with named parameters. And there is no option of using some parameters named and others anonymous, so if there is an `IN` anywhere in the query, then the entire query - and any variation of the query - must use anonymous parameters.

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> What about `WHERE foo IN (?,?,?)`.

This is can be automatically handled if your ORM supports it; even a micro-ORM like Dapper does.

Otherwise my go-to solution for this if it isn't supported is to pass the collection as a user-defined table type, filled with the values. you can either use WHERE IN or join on this table variable.

EDIT: my perspective on this if from working with SQL Server and .NET. I don't know enough about Python or PHP development to comment on those.

If you're using an ORM then you don't worry about creating the prepared statement or SQL string yourself, so the entire issue is moot (See GP post).

It's not moot: Dapper doesn't auto-generate the query for you, it's just a thin layer over .NET's SqlClient to reduce boilerplate of converting to and from C# objects.

You still have to write your SQL statements, and in your example you'd still be able to refer to your array by name:

    select SomethingID where AnotherThing in @yourNamedArrayParameter

More here: https://github.com/StackExchange/Dapper#list-support

If you're not using Dapper just use a user-defined table type to hold your data and join on it instead of using WHERE IN.

Very cool, thank you!

Here is some simple documentation on how it is done in C#: https://msdn.microsoft.com/en-us/library/system.data.sqlclie... It is slightly verbose, but I find it immensively valuable. No ORM required.

That documentation does not address the use case that I mention, in which the number of parameters is unknown.

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