大约有 40,000 项符合查询结果（耗时：0.0342秒） [XML]
MySQL, update multiple tables with one query
...'blah';
To see what this is going to update, you can convert this into a select statement, e.g.:
SELECT t2.t1_id, t2.t3_id, t1.a, t2.b, t2.c AS t2_c, t3.c AS t3_c
FROM t1
INNER JOIN t2 ON t2.t1_id = t1.id
INNER JOIN t3 ON t2.t3_id = t3.id
WHERE t1.a = 'blah';
An example using the same tables as...
Unresolved reference issue in PyCharm
...
After all this don't forget to restart. In PyCharm menu select: File --> Invalidate Caches / Restart
share
|
improve this answer
|
follow
...
ReactJS render string with non-breaking spaces
I have some props that has a string that could contain characters such as &.
It also contains spaces. I want to replace all spaces with   .
...
Hidden features of Perl?
...
One of my favourite features in Perl is using the boolean || operator to select between a set of choices.
$x = $a || $b;
# $x = $a, if $a is true.
# $x = $b, otherwise
This means one can write:
$x = $a || $b || $c || 0;
to take the first true value from $a, $b, and $c, or a default of 0...
Extract file basename without path and extension in bash [duplicate]
...til item #7 below).
1st pattern: *\/ matches anything before a literal "/" char.
pattern separator | which in this instance acts like a logical OR.
2nd pattern: .* matches anything after a literal "." -- that is, in bash the "." is just a period char, and not a regex dot.
) end pattern list.
} end ...
How to best display in Terminal a MySQL SELECT returning too many fields?
...
Terminate the query with \G in place of ;. For example:
SELECT * FROM sometable\G
This query displays the rows vertically, like this:
*************************** 1. row ***************************
Host: localhost
Db: mydatabase1
...
#1071 - Specified key was too long; max key length is 1000 bytes
... the best prefix length for a given column? Here's a method to find out:
SELECT
ROUND(SUM(LENGTH(`menu_link`)<10)*100/COUNT(`menu_link`),2) AS pct_length_10,
ROUND(SUM(LENGTH(`menu_link`)<20)*100/COUNT(`menu_link`),2) AS pct_length_20,
ROUND(SUM(LENGTH(`menu_link`)<50)*100/COUNT(`menu_...
How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops
...tep 1: Add VBA reference to "Microsoft VBScript Regular Expressions 5.5"
Select "Developer" tab (I don't have this tab what do I do?)
Select "Visual Basic" icon from 'Code' ribbon section
In "Microsoft Visual Basic for Applications" window select "Tools" from the top menu.
Select "References"
Chec...
Maven2: Best practice for Enterprise Project (EAR file)
...
What helped me a lot was to run the Maven archetype:generate goal and select from one of the archetypes, some of which seem to be updated regularly (in particular JBoss seems to be well maintained).
mvn archetype:generate
Hundreds of archetypes appeared in a numbered list from which to selec...
javac not working in windows command prompt
...anced" tab ⇒ Environment Variables
In "System Variables", scroll down to select "PATH" ⇒ Edit
(( now read the following 3 times before proceeding, THERE IS NO UNDO ))
In "Variable value" field, INSERT "c:\Program Files\Java\jdk1.8.0_xx\bin" (Replace xx with the upgrade number and VERIFY that ...