Proper implementation for `dbDataType()`

[nbenn]

Currently we have

adbi/R/dbDataType_AdbiConnection.R

Lines 12 to 18 in 3149da7

	db_data_type <- function(x, drv) {
	if (inherits(x, "blob")) {
	db_data_type_blob(drv)
	} else {
	dbDataType(ANSI(), x)
	}
	}

and

adbi/R/utils.R

Lines 52 to 65 in 3149da7

	db_data_type_blob <- function(drv) {
	if (inherits(drv, "adbcsqlite_driver_sqlite")) {
	"BLOB"
	} else if (inherits(drv, "adbcpostgresql_driver_postgresql")) {
	"bytea"
	} else {
	stop(
	"dbDataType for blob objects unknown for type ",
	paste0(class(drv), collapse = ", "),
	call. = FALSE
	)
	}
	}

How can we do better?

• Have adbcdrivermanager introduce a generic for this?
• Introduce our own generic?

[nbenn]

See also apache/arrow-adbc#1394.