大约有 41,000 项符合查询结果（耗时：0.0311秒） [XML]
ERROR 2006 (HY000): MySQL server has gone away
...L/MariaDB server.
Double check the value was set properly by:
mysql -sve "SELECT @@max_allowed_packet" # or:
mysql -sve "SHOW VARIABLES LIKE 'max_allowed_packet'"
You got a timeout from the TCP/IP connection on the client side.
Solution: Increase wait_timeout variable.
You tried to run a query a...
How do I list all the columns in a table?
...
For Oracle (PL/SQL)
SELECT column_name
FROM user_tab_cols
WHERE table_name = 'myTableName'
For MySQL
SHOW COLUMNS FROM table_name
share
|
i...
How can I unit test Arduino code?
...tiplex four 7 segment displays, one port driving the segments and a second selecting the display. The display code interfaces with the displays via SetSegmentData(char) and SetDisplay(char). I can mock these in my C++ test rig and check that I get the data I expect. For the target I use #define so t...
What is the copy-and-swap idiom?
...y that, but unqualified calls to swap will use our custom swap operator, skipping over the unnecessary construction and destruction of our class that std::swap would entail.)
An in-depth explanation
The goal
Let's consider a concrete case. We want to manage, in an otherwise useless class, a dyn...
How to get primary key column in Oracle?
...
SELECT cols.table_name, cols.column_name, cols.position, cons.status, cons.owner
FROM all_constraints cons, all_cons_columns cols
WHERE cols.table_name = 'TABLE_NAME'
AND cons.constraint_type = 'P'
AND cons.constraint_name = ...
MySQL LIKE IN()?
... might be more efficient, but you'd have to benchmark it to be sure, e.g.
SELECT * from fiberbox where field REGEXP '1740|1938|1940';
share
|
improve this answer
|
follow
...
How to validate an email address using a regular expression?
... that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.
75 Answers
...
How to change proxy settings in Android (especially in Chrome) [closed]
... to set proxy settings in Android (especially in Chrome)? I have to change IP on Android during the testing. Or there is some soft which can help me to solve this issue...
...
How do you sign a Certificate Signing Request with your Certification Authority?
...cConstraints = CA:FALSE
keyUsage = digitalSignature, keyEncipherment
subjectAltName = @alternate_names
nsComment = "OpenSSL Generated Certificate"
####################################################################
[ alternate_names ]
DNS.1 = example.com
DNS.2 =...
ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'db'
... problem was:
To see which user you are, and whose permissions you have:
select user(), current_user();
To delete the pesky anonymous user:
drop user ''@'localhost';
share
|
improve this answe...