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MySQL Removing Some Foreign keys
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You can use this to find foreign key constraints: SELECT * FROM information_schema.table_constraints WHERE constraint_schema = '<your db name>' AND constraint_type = 'FOREIGN KEY'
– Gayan Dasanayake
Aug 26 '17 at 2:48
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Right query to get the current number of connections in a PostgreSQL DB
...ires aren't equivalent. The equivalent version of the first one would be:
SELECT sum(numbackends) FROM pg_stat_database;
In that case, I would expect that version to be slightly faster than the second one, simply because it has fewer rows to count. But you are not likely going to be able to measu...
Xcode 5: Code signing entitlement errors
... This worked for me too. I am using Xcode 6.3. I was unable to select apple dev account for code signing. Totally unrelated error message was displayed everytime "ios app id 'xxxxxxxxx' does not support changes to the maps feature". A simple xcode restart fixed it for me.
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How to use range-based for() loop with std::map?
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If copy assignment operator of foo and bar is cheap (eg. int, char, pointer etc), you can do the following:
foo f; bar b;
BOOST_FOREACH(boost::tie(f,b),testing)
{
cout << "Foo is " << f << " Bar is " << b;
}
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Union Vs Concat in Linq
...ence is not changed.
If you will override Equals and GetHashCode (used to select distinct items), then items will not be compared by reference:
class X
{
public int ID { get; set; }
public override bool Equals(object obj)
{
X x = obj as X;
if (x == null)
re...
Dynamically adding a form to a Django formset with Ajax
...ice');
});
</script>
In a javascript file:
function cloneMore(selector, type) {
var newElement = $(selector).clone(true);
var total = $('#id_' + type + '-TOTAL_FORMS').val();
newElement.find(':input').each(function() {
var name = $(this).attr('name').replace('-' + (t...
What is the proper way to re-attach detached objects in Hibernate?
...k);
});
And Hibernate is going to execute the following SQL statements:
SELECT
b.id,
b.author AS author2_0_,
b.isbn AS isbn3_0_,
b.title AS title4_0_
FROM
book b
WHERE
b.id = 1
-- Merging the Book entity
UPDATE
book
SET
author = 'Vlad Mihalcea',
isbn = '978-9...
Cause of a process being a deadlock victim
I have a process with a Select which takes a long time to finish, on the order of 5 to 10 minutes. I am currently not using NOLOCK as a hint to the MS SQL database engine. At the same time we have another process doing updates and inserts into the same database and same tables. The first pr...
How to use the “required” attribute with a “radio” input field
...buttons they must all have the same name value. This allows only one to be selected at a time and applies required to the whole group.
<form>
Select Gender:<br>
<label>
<input type="radio" name="gender" value="male" required>
Male
</label><b...
SQL - many-to-many table primary key
...es are read far more often than written. That makes anything you do on the select side far more relevant than anything on the insert side.
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