大约有 40,000 项符合查询结果（耗时：0.0613秒） [XML]
MySQL Fire Trigger for both Insert and Update
...me.
1. Define the INSERT trigger:
DELIMITER //
DROP TRIGGER IF EXISTS my_insert_trigger//
CREATE DEFINER=root@localhost TRIGGER my_insert_trigger
AFTER INSERT ON `table`
FOR EACH ROW
BEGIN
-- Call the common procedure ran if there is an INSERT or UPDATE on `table`
-- NEW.id is an...
How to use SSH to run a local shell script on a remote machine?
...ssh user@host2 <<'END2'
# Another bunch of commands on another host
wall <<'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.secureftp-test.com <<'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
You can actually have a conversation with some services like telnet, ftp, etc. But remember that...
Can't open config file: /usr/local/ssl/openssl.cnf on Windows [duplicate]
...
The solution is running this command:
set OPENSSL_CONF=C:\OpenSSL-Win32\bin\openssl.cfg
or
set OPENSSL_CONF=[path-to-OpenSSL-install-dir]\bin\openssl.cfg
in the command prompt before using openssl command.
Let openssl know for sure where to find its .cfg file.
Al...
Why was the switch statement designed to need a break?
...
Many answers seem to focus on the ability to fall through as the reason for requiring the break statement.
I believe it was simply a mistake, due largely because when C was designed there was not nearly as much experience with how these constructs would be used.
Peter ...
What is RSS and VSZ in Linux memory management
...
RSS is the Resident Set Size and is used to show how much memory is allocated to that process and is in RAM. It does not include memory that is swapped out. It does include memory from shared libraries as long as the pages from those libraries are actually in memory. It does include all st...
Set value to NULL in MySQL
... can be inserted/updated without quotes:
INSERT INTO user (name, something_optional) VALUES ("Joe", NULL);
UPDATE user SET something_optional = NULL;
share
|
improve this answer
|
...
Cannot use ref or out parameter in lambda expressions
...e visible on the ref parameter itself. Both within the method and in the caller.
These are somewhat incompatible properties and are one of the reasons they are disallowed in lambda expressions.
share
|
...
NPM cannot install dependencies - Attempt to unlock something which hasn't been locked
I've been trying to run an npm install on my package.json file, but I'm having a lot of trouble. It keeps saying "Error: Attempt to unlock XXX, which hasn't been locked" on all my dependences. Here's one of them:
...
Returning a C string from a function
...F-8 is an example of an mbcs. For the sake of intro, I quietly 'skip over' all of this.
Memory:
This means that a string like "my string" actually uses 9+1 (=10!) bytes. This is important to know when you finally get around to allocating strings dynamically.
So, without this 'terminating zero', y...
Send string to stdin
...
@Pyrolistical yes! Especially useful when mastering for example a perl oneliner from a command line - easy editing of perl's arguments without the need much backward movements with a cursor. :)
– jm666
Feb 12 '1...