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How do I update an entity using spring-data-jpa?
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Identity of entities is defined by their primary keys. Since firstname and lastname are not parts of the primary key, you cannot tell JPA to treat Users with the same firstnames and lastnames as equal if they have different userIds.
So, if you want to update a User identified by its firstname a...
MongoDB: Combine data from multiple collections into one..how?
...you can use as an _id.
For example, let's say you have a users collection and a comments collection and you want to have a new collection that has some user demographic info for each comment.
Let's say the users collection has the following fields:
_id
firstName
lastName
country
gender
age
And...
Objective-C ARC: strong vs retain and weak vs assign
...ew memory management attributes for properties introduced by ARC, strong and weak .
8 Answers
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select and update database record with a single queryset
How do I run an update and select statements on the same queryset rather than having to do two queries:
- one to select the object
- and one to update the object
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Merge up to a specific commit
...med newbranch from the master branch in git. Now I have done some work and want to merge newbranch to master ; however, I have made some extra changes to newbranch and I want to merge newbranch up to the fourth-from-the-last commit to master .
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How do I add indices to MySQL tables?
...y large MySQL table with about 150,000 rows of data. Currently, when I try and run
7 Answers
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Add unique constraint to combination of two columns
I have a table and, somehow, the same person got into my Person table twice. Right now, the primary key is just an autonumber but there are two other fields that exist that I want to force to be unique.
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How to avoid “if” chains?
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You can use an && (logic AND):
if (executeStepA() && executeStepB() && executeStepC()){
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}
executeThisFunctionInAnyCase();
this will satisfy both of your requirements:
executeStep<X>() should evaluate only if the pre...
startActivityForResult() from a Fragment and finishing child Activity, doesn't call onActivityResult
...bugged the code, i see onActivityresult() of FirstAcivity.Java gets called and onActivityresult() of FragmentA.Java never get called. Please help.
– Mr Roshan Pawar
Jun 13 '13 at 11:46
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Configure Flask dev server to be visible across the network
... To set to a specific ip app.run(host="192.168.1.7",port=5010) handy if your pc has a few ip's
– lxx
Jan 2 '15 at 3:29
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