CODEWITHSUNDEEP
gosqlx
evocatus
evocatus

Reputation: 141

Sqlx "missing destination name" for struct tag through pointer

I have a model like this:

type Course struct {
    Name string `db:"course_name"`
}

type Group struct {
    Course *Course
}
type Groups []Group

And when i try to do sqlx.Select for Groups with a query like this:

SELECT c.name as course_name FROM courses as c;

I get

missing destination name course_name in *main.Groups

error.

What is the issue with this code?

Upvotes: 6

Views: 22719

Answers (3)

transistor
transistor

Reputation: 921

Ok, so when you are using an embbeded struct with Sqlx, capitalization is important, at least in my case.

You need to refer to the embedded struct in your sql, like so:

select name as "course.name" from courses...

Notice that course is lower case and the naming involves a dot/period between table and column.

Then your Get or Select should work just fine.

Upvotes: 1

evocatus
evocatus

Reputation: 141

I changed Course *Course to Course Course - no effect. When i made it embedded like this:

type Group struct {
    Course
}

it worked.

This is also valid:

type Group struct {
    *Course
}

Looks like sqlx doesn't understand anything except embedded fields.

Upvotes: 2

Decade Moon
Decade Moon

Reputation: 34286

You need to use sqlx.Select when you are selecting multiple rows and you want to scan the result into a slice, as is the case for your query, otherwise use sqlx.Get for a single row.

In addition, you can't scan directly into a Group struct because none of its fields are tagged (unlike the Course struct), and the Course field isn't embedded.

Try:

course := Course{}
courses := []Course{}

db.Get(&course, "SELECT name AS course_name FROM courses LIMIT 1")
db.Select(&courses, "SELECT name AS course_name FROM courses")

Upvotes: 5

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