大约有 30,000 项符合查询结果（耗时：0.0507秒） [XML]
Create unique constraint with null columns
...
Create two partial indexes:
CREATE UNIQUE INDEX favo_3col_uni_idx ON favorites (user_id, menu_id, recipe_id)
WHERE menu_id IS NOT NULL;
CREATE UNIQUE INDEX favo_2col_uni_idx ON favorites (user_id, recipe_id)
WHERE menu_id IS NULL;
This way, there can only be one combination of (user_...
How to add an auto-incrementing primary key to an existing table, in PostgreSQL?
...le named test1, to which you want to add an auto-incrementing, primary-key id (surrogate) column. The following command should be sufficient in recent versions of PostgreSQL:
ALTER TABLE test1 ADD COLUMN id SERIAL PRIMARY KEY;
Older Versions of PostgreSQL
In old versions of PostgreSQL (prior ...
Disable a Maven plugin defined in a parent POM
...or me when disabling Findbugs in a child POM:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>findbugs-maven-plugin</artifactId>
<executions>
<execution>
<id>ID_AS_IN_PARENT</id> <!-- id is necessary ...
Remove Trailing Slash From String PHP
... I'd also suggest using DIRECTORY_SEPARATOR instead of '/' if using file paths so it works on all platforms.
– Brad
Apr 9 at 7:21
add a comment
|
...
iPhone Keyboard Covers UITextField
...is for you with NO LINE OF CODE, only need to drag and drop related source file to project. IQKeyboardManager also support Device Orientation, Automatic UIToolbar Management, keyboardDistanceFromTextField and much more than you think.
Here is the Control Flow Chart:
Step1:- Added global notific...
How do I create a file and write to it in Java?
What's the simplest way to create and write to a (text) file in Java?
33 Answers
33
...
How to ignore certain files in Git
I have a repository with a file, Hello.java . When I compile it, an additional Hello.class file is generated.
21 Answers...
关于php的socket初探 - PHP - 清泛IT论坛，有思想、有深度
...
static $id = 0;
static $ct = 0;
$ct_last = $ct;
&...
What exactly does the enable-background attribute do?
...en used on the root <svg> element due to Inkscape adding it on every file (causing perf issues). As of today, other browsers still do not support In1/In2=BackgroundImage though, only IE and Edge do.
– FremyCompany
May 19 '17 at 3:08
...
android.widget.Switch - on/off event listener?
I would like to implement a switch button, android.widget.Switch (available from API v.14).
10 Answers
...