I am working on code which runs sql scripts with SqlPlus. Most of the scripts have DDL in them, which requires a / (forward slash) to run the buffer. Some of the scripts are missing the slash. I have tried running the script like #script.sql and then /, but it sometimes tries to create something twice. I want to run the show errors command at the end as well, and sometimes that caused trouble for me if the / was missing.
So, I changed to #script . (period) show errors. This works when the / is present in the file, but now if the / is missing in the file, if messes up by not creating the object.
We tried to have some logic to check for ends with / in the file, but that is a messy option in my opinion. I had false positives, and it isn't a perfect solution.
I thought about trying to run with another tool, but since the company I work for has released this already, and customers expect it to run with sqlplus, and may include commands that only work in sqlplus; that are not JDBC compliant, I don't think that is an adequate solution.
I am thinking now that if I could check if / had been run on the current buffer and do / only if it had not, that would be a great solution, perhaps perfect, but I can't find any documentation that such a command exists. Is there another way to solve the problem? Does such a command exist?
Thanks!
SQLPlus is pretty limited. There's no control mechanism to do an IF/THEN even if you determine whether the buffer had been sent.
One thing you can do is, before a script is run, you call
exec begin raise login_denied; end;
After the script, call
#show sqlcode
If that still shows 1017 (the error code for login_denied), then you can be pretty sure that the script didn't execute any SQL statement. You can use a user defined error code if you prefer, such as raise_application_error(-20123,'dummy');
Note that I included a # prefix in the show statement. That runs the command without affecting the contents of the buffer so if you find nothing has been executed, you could try running the buffer contents with the slash.
If you have a single script that contains multiple DDLs (eg a table plus indexes/grants/constraints...) then you still run the risk of not running a final command if it didn't have the slash.
Related
(Please, help me adjust title and tags.)
When I run connmanctl I get a different prompt,
enrico:~$ connmanctl
connmanctl>
and different commands are available, like services, technologies, connect, ...
I'd like to know how this thing works.
I know that, in general, changing the prompt can be just a matter of changing the variable PS1. However this thing alone (read "the command connmanctl changes PS1 and returns) wouldn't have any effect at all on the functionalities of the commands line (I would still be in the same bash process).
Indeed, the fact that the available commands are changed, looks to me like the proof that connmanctl is running all the time the prompt is connmanctl>, and that, upon running connmanctl, a while loop is entered with a read statement in it, followed by a bunch of commands which process the the input.
In this latter scenario that I imagine, there's not even need to change PS1, as the connmanctl> line could simply be obtained by echo -n "connmanctl> ".
The reason behind this curiosity is that I'm trying to write a wrapper to connmanctl. I've already written it, and it works as intended, except that I don't know how to properly setup the autocompletion feature, and I think that in order to do so I first need to understand what is the right way to write an interactive shell script.
I have a ruby script, apparently correct, that sometimes stops working (probably on some calls to Postgresql through the pg gem). The problem is that it freezes but doesn't produce any error, so I can't see the line number and I always have to isolate the line by using puts "ok1", puts "ok2", etc. and see where the script stops.
Is there any better way to see the current line being executed (without changing the script)? And maybe the current stack?
You could investigate ruby-debug a project that has been rewritten several times for several different versions of ruby, should allow you to step through your code line by line. I personally prefer printf debugging in a lot of cases though. Also, if I had to take an absolutely random guess at your problem, I might investigate whether or not you're running into a race condition and/or deadlock in your DB.
I have a script named program.rb and would like to write a script named main.rb that would do the following:
system("ruby", "program.rb")
constantly check if program.rb is running until it is done
if program.rb has reached completion
exit main.rb
end
otherwise keep doing this until program.rb reaches completion{
if program.rb is not running and stopped before completing
restart program.rb from where it left off
end}
I've looked into Pidify but could not find a way to apply it to fit this exactly the right way...
Any help in how to approach this script would be greatly appreciated!
Update:
I could figure out how to resume running the script from where it left off in program.rb if there's no way to do it in main.rb
It's impossible to "restart script from where it left off" without full cooperation from the program.rb. That is, it should be able to advertise its progress (by writing current state to a file, maybe?) and be able to start correctly from a step specified in ARGV. There's no external ruby magic that can replace this functionality.
Also, if a program terminated abnormally, it means one of two things:
the error is (semi-)permanent (disk is full, no appropriate access rights to a file, etc). In this case, simply restarting the program would cause it to fail again. And again. Infinite fail loop.
the error is temporary (shaky internet connection). In this case, program should do better job with exception handling and retry on its own (instead of terminating).
In either case, there's no need for restarting, IMHO.
Well, here is one way.
Modify program.rb to take an optional flag argument --restart or something.
When program.rb starts up without this argument it will initialize a file to record its current state. Periodically, it will write whatever it needs into this file to record some kind of checkpoint.
When program.rb starts up with the restart flag, it will read its checkpoint file and start processing at that point. For this to work, it must either checkpoint all state changes or arrange for all processing between checkpoints to be idempotent so it can be repeated without ill effect.
There are lots of ways to monitor the health of program.rb. The best way is with some sort of ping, perhaps something like GET /health_check or a dummy message via a socket or pipe. You could just have a locked file to detect if the lock is still held, or you could record the PID on startup and check that it still exists.
I have a RHEL 5 system and have been trying to get a batch of 3-4 scripts each in a separate variables and they are not working as expected.
I tried using following syntax which I saw a lot of people on this site use and should really work, though for some reason it doesn't work for me.
Syntax -
testvar=`sqlplus -s foo/bar#SCHM <<EOF
set pages 0
set head off
set feed off
#test.sql
exit
EOF`
Now, I have access to the sqlplus command from the oracle bin folder and have also set the ORACLE_HOME and ORACLE_PATH variables exported (I echoed them just to ensure they are actually working).
However, I keep getting the error saying - "you need to set EXPORT for ORACLE_HOME" even though I have confirmed from everyone that I am indeed using the correct path.
Another question I have is once I get the script output (which is numeric number in bits or bytes) value in a variable (There will be 4-5 variables as there are 4-5 scripts), how do I convert into human readable output in either MBs or GBs.
Please guide me on this and I assure you that I will post everything here so that someone in future if gets stuck at the same issue, doesn't have waste time. (and your precious time won't go bad either...)
Thanks in advance,
Brian
I am trying to understand the code in this page: https://github.com/corroded/git-achievements/blob/gh-pages/git-achievements
and I'm kinda at a loss on how it actually works. I do know some bash and shell scripting, but how does this script actually "store" how many times you've used a command(im guessing saving into a text file?) and how does it "sense" that you actually typed in a git command? I have a feeling it's line 464 onwards that does it but I don't seem to quite follow the logic.
Can anyone explain this in a bit more understandable context?
I plan to do some achievements for other commands and I hope to have an idea on HOW to go about it without randomly copying and pasting stuff and voodoo.
Yes on 464 start the script, everything before are helping functions. I dont know how it gets installed, but I would assume you have to call this script instead of the normal git-command. It just checks if the first parameter is achievement, and if not then just (regular) git with the rest parameters is executed. Afterwards he checks if an error happend (if he exits). And then he just makes log_action and check_for_achievments. log_action just writes the issued command with a date into a text file, while achievments scans for that log file for certains events. If you want to add another achievment you have to do it in this check_for_achievments.
Just look how the big case handles it (most of the achievments call the count_function which counts the # usages of the function and matches when a power of 2 is reached).