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Select count(*) from multiple tables
...an I select count(*) from two different tables (call them tab1 and tab2 ) having as result:
18 Answers
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What is the difference between HashSet and List?
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215
Unlike a List<> ...
A HashSet is a List with no duplicate members.
Because a HashSet i...
Order data frame rows according to vector with specific order
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236
Try match:
df <- data.frame(name=letters[1:4], value=c(rep(TRUE, 2), rep(FALSE, 2)))
targe...
Delete multiple records using REST
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92
Is a viable RESTful choice, but obviously has the limitations you have described.
Don't do this...
How to print a number with commas as thousands separators in JavaScript
...th commas as thousands separators. For example, I want to show the number 1234567 as "1,234,567". How would I go about doing this?
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Is there a difference between foreach and map?
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Different.
foreach iterates over a list and applies some operation with side effects to each ...
spring boot default H2 jdbc connection (and H2 console)
I am simply trying to see the H2 database content for an embedded H2 database which spring-boot creates when I don't specify anything in my application.properties and start with mvn spring:run. I can see hibernate JPA creating the tables but if I try to access the h2 console at the URL below the dat...
Difference between open and codecs.open in Python
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Since Python 2.6, a good practice is to use io.open(), which also takes an encoding argument, like the now obsolete codecs.open(). In Python 3, io.open is an alias for the open() built-in. So io.open() works in Python 2.6 and all later ve...
What's the difference between array_merge and array + array?
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The difference is:
The + operator takes the union of the two arrays, whereas the array_merge fu...
What's the right OAuth 2.0 flow for a mobile app
...implement delegated authorization in a Web API for mobile apps using OAuth 2.0. According to specification, the implicit grant flow does not support refresh tokens, which means once an access token is granted for an specific period of time, the user must grant permissions to the app again once the t...