Microsoft Access is a database system
Jet is Access's persistence back-end, and the aspect of Access most likely to interest Tcl developers immediately. Windows has bundled Jet for several years now--write a Jet-dependent application, and it should work fine on any Windows host since Windows 95 (?).
In 2002, Jet was renamed to MSDE. [L1 ] might explain more. It's also called "MDB" and "MSDB".
RS: A simple way to interact with Access is via CSV files (see also the links there) - plain text files with comma-separated values (in German locale, Access does not allow to use commas though, because it is considered decimal separator, so use semicolons instead; Excel accepts commas though...
Scott Gamon: I'm pasting in this c.l.t. post by Kevin Kenny
quoting Kevin Kenny:
You can use database configure to create an Access database - in fact, you don't even need Access on the system. (You do need Jet, but I don't think I've ever seen a Windows box without it.)
Try the following code. It creates an empty MDB file at the location the user gives and then opens it.
package require Tk
package require tclodbc
# Prompt the user for a database to create
# (For opening an existing database, use tk_getOpenFile instead of
# tk_getSaveFile)
set types {
{{Access Databases} {*.mdb} }
}
set fileName [tk_getSaveFile \
-defaultextension .mdb \
-filetypes $types \
-initialdir ~ \
-title "Create Database"]
# Quit if the user cancels.
if { ! [string compare {} $fileName] } {
exit
}
# Create the database. (Omit this if opening an existing database)
set driver {Microsoft Access Driver (*.mdb)}
database configure config_dsn $driver \
[list CREATE_DB=\"[file nativename $fileName]\" "General"]
# emacs: "
# Connect to the database.
set connectString DRIVER=$driver
append connectString \; DBQ=[file nativename $fileName]
append connectString \; {FIL=MS Access}
append connectString \; EXCLUSIVE=Yes
puts $connectString
database db $connectStringRS 2008-06-18: Here's a cute little tool to dump a table of a .mdb database in to stdout in semicolon-separated format:
#!/usr/bin/env tclsh
set usage {
usage: mdb2csv.tcl mdbfile table > csvfile
Dump a MS Access database table to stdout in CSV format.
MS Access must be running for this to succeed.
}
if {[llength $argv] < 2} {puts stderr $usage; exit 1}
proc main argv {
package require dde
foreach {mdbfile table} $argv break
set request "$mdbfile;TABLE $table"
set it [dde request MSAccess $request All]
foreach line [split $it \n] {
puts [string map {\t ;} $line]
}
}
main $argvetdxc: Just a quick note. When using tclodbc to work with Access memo fields, if you insert a record which contain a memo field that contains a large amount of data, you may get a problem rereading it. TclOdbc returns all the data associated with the memo, spurious or otherwise. In a rush (as always) I found the easiest solution is to store the memo as a two element list (or as two separate fields), index 0 contains an integer 'size' of the memo and index 1 the memo itself. Use lrange to extract the actual stored text.
Of course there may be a (lot) better method. If so, please let me know.