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mongodb count num of distinct values per field/key
Is there a query for calculating how many distinct values a field contains in DB.
5 Answers
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How can I shift-select multiple checkboxes like GMail?
In GMail, the user can click on one checkbox in the email list, hold down the Shift key, and select a second checkbox. The JavaScript will then select/unselect the checkboxes that are between the two checboxes.
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find vs find_by vs where
I am new to rails. What I see that there are a lot of ways to find a record:
12 Answers
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Insert multiple rows WITHOUT repeating the “INSERT INTO …” part of the statement?
... done this before years ago, but I can't remember the syntax, and I can't find it anywhere due to pulling up tons of help docs and articles about "bulk imports".
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How to get the insert ID in JDBC?
I want to INSERT a record in a database (which is Microsoft SQL Server in my case) using JDBC in Java. At the same time, I want to obtain the insert ID. How can I achieve this using JDBC API?
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Binding a WPF ComboBox to a custom list
...text to your ConnectionViewModel object?
I copied you code and made some minor modifications, and it seems to work fine.
I can set the viewmodels PhoneBookEnty property and the selected item in the combobox changes, and I can change the selected item in the combobox and the view models PhoneBookEnt...
How to set selected value of jquery select2?
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To dynamically set the "selected" value of a Select2 component:
$('#inputID').select2('data', {id: 100, a_key: 'Lorem Ipsum'});
Where the second parameter is an object with expected values.
UPDATE:
This does work, just wanted to note that in the new select2, "a_key" is "text" in a standar...
How do PHP sessions work? (not “how are they used?”)
Session files are usually stored in, say, /tmp/ on the server, and named sess_{session_id} . I have been looking at the contents and cannot figure out how they really work.
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Multiple Updates in MySQL
I know that you can insert multiple rows at once, is there a way to update multiple rows at once (as in, in one query) in MySQL?
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MySQL Cannot Add Foreign Key Constraint
So I'm trying to add Foreign Key constraints to my database as a project requirement and it worked the first time or two on different tables, but I have two tables on which I get an error when trying to add the Foreign Key Constraints.
The error message that I get is:
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