docs: explain scanning array_agg (and other PG arrays) into Go slices#2539
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Users hitting a query that uses `array_agg` (or any PG array-returning expression) and who try to scan its result into a struct field often see "unable to assign to *[]int64" and assume the feature is missing. The two-step recipe from jackc#1900 — scan the array scalar into a slice with `QueryRow` / slice-typed `Scan`, and compose slice fields into structs via `CollectRows` / `RowToStructByName` — is the canonical answer but isn't currently discoverable from the package docs. Add a short paragraph with both forms to the PostgreSQL Data Types section of `doc.go` so `go doc pgx` / pkg.go.dev surface the recipe. Closes jackc#1900 Signed-off-by: Ali <alliasgher123@gmail.com>
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Description
Users hitting a query that uses
array_agg(or any PG array-returning expression) and who try to scan its result into a Go slice often seescan error: can't scan into dest[0]: unable to assign to *[]int64and assume the feature isn't supported. The two-step recipe from #1900 — scan the array scalar into a slice withQueryRow/ slice-typedScan, then compose slice fields into structs viaCollectRows+RowToStructByName— is the canonical answer but isn't currently discoverable from the package docs.This PR adds a short paragraph with both forms to the PostgreSQL Data Types section of
doc.gosogo doc pgx/ pkg.go.dev surface the recipe. Docs-only change; no behavior impact.Closes #1900