sqlite error: row value misused

[han-holl]

Hi,

If you do:
pp Items.select([:name, :address])
you get:
#<Sequel::Dataset::_Subclass: "SELECT (name, address) FROM main">

Sqlite3 gives the quite unhelpful message: row value misused, because it doesn't like the parentheses in the select clause.
Switch to braces:
pp Items.select{[:name, :address]}
and
#<Sequel::Dataset::_Subclass: "SELECT name, address FROM main">
is of course ok.
I feel tha sequel shouldn't emit SQL that a database doesn't handle.

Han Holl

[jeremyevans]

I feel tha sequel shouldn't emit SQL that a database doesn't handle.

I feel that's an infeasible goal. For one, Sequel supports a wide variety of SQL features, and not all databases support those features. In some cases, Sequel will raise an error before sending an error to the database (mostly for backwards compatibility), but in general, Sequel does what you ask it to do. If the database doesn't support what you are asking it to do, you should fix your code.

SQLite does not support composite types, so it raises an error. The code you provided works on PostgreSQL, where it returns a composite/row type.

As the documentation explains, Dataset#select accepts multiple arguments, not an array of arguments, so you want: Items.select(:name, :address). Items.select{[:name, :address]} also works, but is less efficient as that uses the virtual row support unnecessarily.

[han-holl]

Ok, I'm sure you're right.
I guess I was a bit miffed by sqlite's extremely unhelpful error message.

Han Holl