Directly selecting values from struct

[ssttevee]

Given the following struct

type Person struct {
	Name string `db:"name"`
	Age int `db:"age"`
}

p := Person{
	Name: "Jon",
	Age: 30,
}

There doesn't seem to be a quick way to directly select all of the data from a struct:

SELECT 'Jon' AS "name", 30 AS "age"

Similar to the way it is interpreted in Dataset.Insert():

goqu.From("table").Insert(&p)
// INSERT INTO "table" ("name", "age") VALUES ("Jon", 30)

The current behaviour is:

goqu.From().Select(&p) // SELECT "name", "age"

and

goqu.From(&p) // SELECT * FROM "name", "age"

The best way I can come up with currently, is something like this:

goqu.From().Select(
	goqu.L("?", p.Name).As("name"),
	goqu.L("?", p.Age).As("age"),
) // SELECT 'Jon' AS "name", 30 AS "age"

I'd like to propose a way to more easily build such a query.

I think there should be a new function, perhaps goqu.V, for explicitly stating that I want to use the value as a literal.

goqu.From().Select(
	goqu.V("Jon").As("name"),
	goqu.V(30).As("age"),
) // SELECT 'Jon' AS "name", 30 AS "age"

goqu.From().Select(goqu.V(p)) // SELECT 'Jon' AS "name", 30 AS "age"

goqu.From().Select(goqu.V(p).As("person")) // SELECT ('Jon', 30) AS "person"

I'm not sure about the interactions with other expressions, or other databases, esp. the tuple syntax. It works in postgres though.

[doug-martin]

I added this in v8.0.1 #113. It just an alias for goqu.L("?", val). Ill close this once I release the new version.