direct to project file

[mdsumner]

This thread shows a way http://www.georeference.org/forum/t153736.3

We'd like to flesh out examples of accessing projection files directly, without configuring the ODBC interface.

This code relies on

• installed version of Manifold 9.0 (not just the free viewer)
• an existing project file at "C:\temp\test.map" or set that to suit

I've tried connection strings that use dev builds of Manifold (as listed in the ODBC interface), but the string is too long (?) and gives an error from the odbc package.

library(DBI)
library(odbc)
filepath <- "C:\\temp\\test.map"

template <- "DRIVER={Manifold 9.0 Project Driver (*.map)};DBQ=%s;Unicode=True;Ansi=False;OpenGIS=True;DSN=Default;"
dstring <- sprintf(template, filepath)

con <- dbConnect(odbc::odbc(), .connection_string = dstring)
dbListTables(con)

## need an existing table name  (mfd_meta is always present)
dbReadTable(con, "mfd_meta")

dbGetQuery(con, "SELECT * FROM mfd_meta")

To use dbplyr tbl_lazy needs a bit more groundwork (not yet pushed to this repo): https://twitter.com/mdsumner/status/1318017630981156864/photo/1

[mdsumner]

Here's some notes on direct configuration (the 64-bit interface lives in /system32/ because of legacy in windows, the 32-bit interface is in /SysWOW64

Here's the system interface for configuring named sources (you don't need a project file name for RODBC or odbc):