Invalid SQL generated for SelectStatements and subqueries.

[weiznich]

Setup

Versions

• Diesel: master (ac30743) / 1.1
• Database: postgres

Feature Flags

• diesel: postgres

Problem Description

Without a explicit select clause diesel will generate invalid sql when using normal select statement as subquery in a IN clause.
This does not happen with BoxedSelectStatements.

What are you trying to accomplish?

table!{
    users{
       id -> Integer,
       name -> Text,
    }
}

table! {
    posts {
        id -> Integer,
        user_id -> Integer,
    }
}

fn test(conn: &PgConnection) {
    let subquery = users::table.filter(users::id.eq(1));
    let query = posts::table.filter(posts::user_id.eq_any(subquery));
    query.execute(conn).unwrap();
}

What is the expected output?

A compiler error.

What is the actual output?

The program compiles fine, but errors with a invalid query at runtime.
DatabaseError(__Unknown, "subquery has too many columns")

Are you seeing any additional errors?

No

Steps to reproduce