Scan into embedded structs

[JeremyCraven]

Is your feature request related to a problem? Please describe.
Being able to use the built in goqu functionality like ScanStructContext and ScanStructsContext is great and makes for concise, readable code. However, I have not yet found a way to scan into a struct that has embedded structs within it.

Describe the solution you'd like
A simple example of something we would like to be able to do with goqu below.

Let's say there are two tables (table1 and table2) and we write a query to join these tables and select all columns from both the tables. I want to scan into a struct that looks like this rows struct that contains structs that define all the columns for table1 and table 2.

var rows []struct {
  Table1 table1Model `db:"table1"`
  Table2 table2Model `db:"table2"`
}

var table1Model struct {
  col1 datatype `db:"col1"`
  col2 datatype `db:"col2"`
}

var table2Model struct {
  col1 datatype `db:"col1"`
  col2 datatype `db:"col2"`
}

The query would look roughly like this.

goqu.From("table1").
  Prepared(true).
  InnerJoin(
    goqu.T("table2"),
    goqu.On(goqu.T("table1).Col("col1")Eq(goqu.T("table2").Col("col2"))),
  ).
  Select(
    goqu.L("table1"."col1" as "table1.col1"),
    goqu.L("table1"."col2" as "table1.col2"),
    goqu.L("table2"."col1" as "table2.col1"),
    goqu.L("table2"."col2" as "table2.col2"),
  ).
  ScanStructsContext(ctx, &rows)

Describe alternatives you've considered
Right now I can accomplish this by using the ToSQL() method on my query and then executing the query with sqlx because the sqlx StructScan method supports scanning into nested structs.

Dialect

• postgres
• mysql
• sqlite3

Additional context
This is for sure a nice to have in goqu as it is not blocking functionality at the moment, but could help clean up a lot of code by using only goqu to accomplish these queries.

[doug-martin]

Thank you for the feature request! If you want to open a PR adding the functionality go for it!

If you don't open a PR I'll take a look at how sqlx handles this.

[doug-martin]

@JeremyCraven just added this in #171 let me know what you think and I'll merge.

[doug-martin]

Released as v9.4.0

[aliksend]

As I see it doesn't support nullable embedded structs, that can be receiver using OUTER JOIN. Is there any workaround to get it in one request?

[JeremyCraven]

@JeremyCraven just added this in #171 let me know what you think and I'll merge.

The notification must have slipped through awhile back, but this is definitely being leveraged. Thank you.

[aliksend]

this is definitely being leveraged

So do you plan to implement it?