V3 version with backward comp

backend/internal/db/queries/resource_variants.sql

@@ -0,0 +1,21 @@
+-- name: CreateResourceVariant :one
+INSERT INTO resource_variants (resource_id, variant_type, page_number, width, height, mime_type, generated_by, storage_key)
+VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+RETURNING *;
+
+-- name: GetVariantsByResourceID :many
+SELECT * FROM resource_variants
+WHERE resource_id = $1
+ORDER BY page_number ASC, variant_type ASC;
+
+-- name: GetVariantByID :one
+SELECT * FROM resource_variants
+WHERE id = $1 LIMIT 1;
+
+-- name: DeleteVariantsByResourceID :exec
+DELETE FROM resource_variants WHERE resource_id = $1;
+
+-- name: GetBestVariant :one
+SELECT * FROM resource_variants
+WHERE resource_id = $1 AND variant_type = $2 AND page_number = 1
+LIMIT 1;