大约有 40,000 项符合查询结果（耗时：0.0414秒） [XML]
How to map a composite key with JPA and Hibernate?
...
To map a composite key, you can use the EmbeddedId or the IdClass annotations. I know this question is not strictly about JPA but the rules defined by the specification also applies. So here they are:
2.1.4 Primary Keys and Entity Identity
...
A composite primary key must
correspon...
Surrogate vs. natural/business keys [closed]
... If you have multiple "candidate" keys (fields or same-size collections of fields that are NOT NULL UNIQUE) then you are likely in violation of Boyce-Codd Normal Form. BCNF is beyond 3NF, so not many people worry about it. There are situations, however, where being in BCNF is very helpful....
How to install latest version of git on CentOS 7.x/6.x
...s/7/git/x86_64/wandisco-git-release-7-2.noarch.rpm
Install the latest version of Git 2.x:
yum install git
Verify the version of Git that was installed:
git --version
As of 02 Mar. 2020, the latest available version from WANDisco is 2.22.0.
...
list every font a user's browser can display
...
The JavaScript version is a bit flaky. It gets fonts by iterating through known fonts and testing.
The most accurate way (albeit having to use a propriety plugin) is to use Flash. Here you can get the list of fonts without having to test for ...
What are the differences between “=” and “
...ightly different operator precedence (which determines the order of evaluation when they are mixed in the same expression). In fact, ?Syntax in R gives the following operator precedence table, from highest to lowest:
…
‘-> ->>’ rightwards assignment
‘<- <<-’ ...
S3 Static Website Hosting Route All Paths to Index.html
...bucket, rather than just doing a full redirect. Then my javascript application could parse the URL and serve the proper page.
...
Difference between dispatch_async and dispatch_sync on serial queue?
...
Yes. Using serial queue ensure the serial execution of tasks. The only difference is that dispatch_sync only return after the block is finished whereas dispatch_async return after it is added to the queue and may not finished.
for this code
dispatch_async(_serialQueue, ^...
How to run travis-ci locally
...$RANDOM"
View the build log, open the show more button for WORKER INFORMATION and find the INSTANCE line, paste it in here and run (replace the tag after the colon with the newest available one):
INSTANCE="travisci/ci-garnet:packer-1512502276-986baf0"
Run the headless server
docker run --name $B...
AngularJS ng-if with multiple conditions
... <label ng-repeat="(key,val) in list">
<input type="radio" name="localityTypeRadio" ng-model="$parent.localityTypeRadio" ng-value="key" />{{key}}
<div ng-if="key == 'City' || key == 'County'">
<pre>City or County !!! {{$parent.localityTypeRadi...
What are Transient and Volatile Modifiers?
...hey are unrelated.
The transient modifier tells the Java object serialization subsystem to exclude the field when serializing an instance of the class. When the object is then deserialized, the field will be initialized to the default value; i.e. null for a reference type, and zero or false for a ...