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Cannot change column used in a foreign key constraint
... DELETE ) will wait till timeout or UNLOCK TABLES; is executed
http://dev.mysql.com/doc/refman/5.5/en/lock-tables.html
EDIT 2: OP asked for a more detailed explanation of the line "The type and definition of foreign key field and reference must be equal. This means your foreign key disallows chang...
How do I check CPU and Memory Usage in Java?
... }
public String DiskInfo() {
/* Get a list of all filesystem roots on this system */
File[] roots = File.listRoots();
StringBuilder sb = new StringBuilder();
/* For each filesystem root, print some info */
for (File root : roots) {
sb.append...
B-Tree vs Hash Table
In MySQL, an index type is a b-tree, and access an element in a b-tree is in logarithmic amortized time O(log(n)) .
5 Answ...
How do I put an 'if clause' in an SQL string?
So here's what I want to do on my MySQL database.
9 Answers
9
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How to make Sequelize use singular table names
...ames
freezeTableName: true
}
}
var sequelize = new Sequelize('mysql://root:123abc@localhost:3306/mydatabase', opts)
Now when you define your entities, you don't have to specify freezeTableName: true:
var Project = sequelize.define('Project', {
title: Sequelize.STRING,
descrip...
Run a Docker image as a container
... If you need to add an environment variable you can do docker run -i -t -e ROOT_PASSWORD=root ubuntu:12.04
– Balaji Radhakrishnan
Dec 16 '17 at 14:23
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Data binding to SelectedItem in a WPF Treeview
...e namespace declaration):
<TreeView ItemsSource="{Binding Path=Root.Children}" local:TreeViewHelper.SelectedItem="{Binding Path=SelectedItem, Mode=TwoWay}">
</TreeView>
Now you can bind the selected item, and also set it in your view model to change it programmatically, s...
GROUP_CONCAT ORDER BY
...
@aleroot, Is this query MySQL specific?
– Pacerier
Apr 30 '15 at 20:24
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Can table columns with a Foreign Key be NULL?
... otherwise an empty string can be passed as default. This is the case with MySQL, and results in an integrity error on update.
– CodeMantle
Mar 21 at 8:28
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PHP mkdir: Permission denied problem
..., all you need it's to obtain correct path. I did it this way:
<?php
$root = $_SERVER["DOCUMENT_ROOT"];
$dir = $root . '/somefolder/';
if( !file_exists($dir) ) {
mkdir($dir, 0755, true);
}
?>
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