Creating a copy of a database -- best practice? - checking email - did not come through before
Ok, I haven't done this in a while, but I think I have done this a few ways.
First, by "metadata" of the database, I assume you mean stored procedures, maybe table triggers, database comment field?
I'll also assume you are trying to run from within an .exe (so commands like COPY PROCEDURES TO... and APPEND PROCEDURES FROM ... will not be available)
So...
1) if you know the "data model" of the dbc, you can open it like a table - then look for the metadata items you want (the stored procedure code, trigger code, etc). Do a SCATTER MEMO NAME ... Then open the other DBC as a table and do an APPEND FROM NAME ... After everything is copied that way I think you will want to do a PACK DATABASE or maybe VALIDATE DATABASE on the backup. I seem to recall doing that.
2) after you've copied all the tables, copy the "database files" with "COPY FILE <orig> TO <backup>" - copy the dbc, dct, and dcx this way. Again a PACK or VALIDATE database may be needed afterwards. And of course, be careful with this, test it out, etc. But I definitely used this approach before.
3) if you are not worried about the tables being opened at the time of doing the backup, you could just do the "COPY FILE <orig> TO <backup>" - that command allows paths in the from/to. Also, I think it allows wildcards, so you could do a complete copy in 1 command. Of course, the downside is the assumption of files being closed.
-HTH, -Charlie
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On 2/27/2019 12:22 PM, mbsoftwaresolutions@mbsoftwaresolutions.com wrote: I can easily do something like this:
CREATE DATABASE C:\Backup\MyDBC.dbc OPEN DATABASE C:\Production\MyDBC.dbc liNumTables = adbobjects(laTables,'TABLE') for ii = 1 to liNumTables lcFile = forceext("C:\BACKUP" + laTables[ii],'dbf') use laTables[ii] copy to (lcFile) database C:\Backup\MyDBC.dbc with cdx use endfor
...and that would get me a copy of all of the tables with their indexes. Great. But what's the easiest way to get all of the DBC meta-data into that new Backup database copy? I can't USE the MyDBC.dbc and do a COPY TO as that only makes the result a DBF and FPT.
Trying to think about a good disaster recovery plan (besides using CleverFox from Rick Schummer and Frank Perez...which is probably the best option!) for automating backups at the client who just got that ransomware virus.
tia, --Mike
On 2019-03-02 08:14, Charlie-gm wrote:
Ok, I haven't done this in a while, but I think I have done this a few ways.
First, by "metadata" of the database, I assume you mean stored procedures, maybe table triggers, database comment field?
I'll also assume you are trying to run from within an .exe (so commands like COPY PROCEDURES TO... and APPEND PROCEDURES FROM ... will not be available)
So...
- if you know the "data model" of the dbc, you can open it like a
table - then look for the metadata items you want (the stored procedure code, trigger code, etc). Do a SCATTER MEMO NAME ... Then open the other DBC as a table and do an APPEND FROM NAME ... After everything is copied that way I think you will want to do a PACK DATABASE or maybe VALIDATE DATABASE on the backup. I seem to recall doing that.
- after you've copied all the tables, copy the "database files" with
"COPY FILE <orig> TO <backup>" - copy the dbc, dct, and dcx this way. Again a PACK or VALIDATE database may be needed afterwards. And of course, be careful with this, test it out, etc. But I definitely used this approach before.
- if you are not worried about the tables being opened at the time of
doing the backup, you could just do the "COPY FILE <orig> TO <backup>"
- that command allows paths in the from/to. Also, I think it allows
wildcards, so you could do a complete copy in 1 command. Of course, the downside is the assumption of files being closed.
Hi Charlie,
I've got VFP available so COPY/APPEND PROCEDURES is available. So I wrote a quick PRG and got the stored procedures just fine with that...but the part that's missing now is the table-specific data like default values (important as some call the usual newid('table') function in the default PK field) and captions (not important).
--Mike
Below is a function to backup a database from a source folder to a target folder, including all triggers, stored procedures, default field values etc. I do not think there was anything wrong with the original "table" copying code that Mike had, but I did not have that email handy when I did this. So just be advised if there was something special in that original code, my code below may not handle it, etc. This code should work even if the source database is open as well as tables in that database being open by another application. Of course, the DB and tables are expected to be open in SHARED mode (aka, non-EXCLUSIVE). Also note that if this code is placed directly in an application, it will close all databases/tables. So if the application needs to have this function, some "environmental saving/restore" code would need to be added (pretty simple to do with the AUSED() function, etc).
This uses my "Option 3" method from the earlier email. Essentially, after all the base data is copied, a direct "file copy" on the DBC data is performed. Technically, COPY FILE ... could probably be used for all files of the DB, but by using the table "COPY" (not COPY FILE) it drastically reduces any potential for 'corruption' due to multi-user actions, etc. And, using COPY FILE only on the "database container" files is quite reasonably safe since DATABASE LEVEL modifications are generally not a "user" operation and so could be avoided during the backup process.
It goes without saying, before using in production, this code should be thoroughly tested, customized, etc.
HTH, -Charlie
PS. Please don't make fun of my variable names - I was in a hurry when I gen'd this up (hahahaha)
*---------------------------------- FUNCTION db_backup *-- purpose: create a backup copy of a VFP database, including all *-- stored procedures, triggers, etc *-- Parameters: *-- from_db: full path qualified (x:\sample\one\dbname) *-- to_db: full path qualified *-- *-- Assupmtions: *-- - this code is mainly 'proof of concept' code, so several *-- sections should be checked before production use *-- - the target db (to_db) is not OPEN by any application
PARAMETERS from_db, to_db LOCAL target_dir, ntbls, ctbl, cdbname, from_dir *-- should "harden" this code before production - e.g. ensure source *-- db exists, decide and code what should be done if destination db *-- already exists (only want one db in the backup folder, etc)
*-- Warning! Exclusive being off is pretty much required for this *-- code. If your other code needs Exclusive ON, change code to *-- turn it back on in the end of this function. SET EXCLUSIVE OFF
*-- Warning! the following block deletes any VFP database files in *-- the target folder. So this needs to be changed if that folder *-- is being used to backup other DBs, free tables, etc.
target_dir = ADDBS(JUSTPATH(to_db)) DELETE FILE (target_dir + "*.db?") DELETE FILE (target_dir + "*.dct") DELETE FILE (target_dir + "*.dcx") DELETE FILE (target_dir + "*.cdx") DELETE FILE (target_dir + "*.fpt")
*-- Create the target database and copy all the base table data CREATE DATABASE (to_db) OPEN DATABASE (from_db) ntbls = ADBOBJECTS(_atbls, 'TABLE') FOR ni = 1 TO ntbls ctbl = ALLTRIM(_atbls[ni]) *-- if the table being copied is opened elsewhere in the app *-- need to use it 'again' IF USED(ctbl) USE (ctbl) AGAIN IN 0 ALIAS TMPCOPY ELSE USE (ctbl) IN 0 ALIAS TMPCOPY ENDIF SELECT TMPCOPY COPY TO (target_dir + ctbl) DATABASE (to_db) WITH cdx USE IN ("TMPCOPY") ENDFOR
*-- now, to get all stored procs, etc, need to copy the dbc. Test *-- this code thoroughly CLOSE DATABASES all
*-- this assumes the backup db should have the same name as the *-- source db. If there is a desire to rename the backup db, *-- this code should be changed to grab the target name from *-- the to_db parameter cdbname = JUSTSTEM(from_db) from_dir = ADDBS(JUSTPATH(from_db))
*-- NOTE: turning SAFETY off to avoid pop-up warning SET SAFETY OFF COPY FILE (from_dir + cdbname + ".dbc") to ; (target_dir + cdbname + ".dbc") COPY FILE (from_dir + cdbname + ".dcx") to ; (target_dir + cdbname + ".dcx") COPY FILE (from_dir + cdbname + ".dct") to ; (target_dir + cdbname + ".dct") SET SAFETY ON
*-- this might not be necessary, but including it for *-- conceptual consideration COMPILE DATABASE (to_db) OPEN DATABASE (to_db) EXCLUSIVE VALIDATE DATABASE CLOSE DATABASE
RETURN
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Charlie-gm -
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