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PG undefinedtable error relation users does not exist
...migrations. It will only use the
contents of the current schema.rb file. If a migration can't be rolled back,
rake db:reset may not help you. To find out more about dumping the schema see
Schema Dumping and You section. Rails Docs
If the trick doesn't help, drop the database, then re-create ...
How do I execute a stored procedure once for each row returned by query?
...ter than manual while-loops; more details in this SO question
ADDENDUM 2: if you will be processing more than just a few records, pull them into a temp table first and run the cursor over the temp table; this will prevent SQL from escalating into table-locks and speed up operation
ADDENDUM 3: and ...
How to use Checkbox inside Select Option
...eckboxes() {
var checkboxes = document.getElementById("checkboxes");
if (!expanded) {
checkboxes.style.display = "block";
expanded = true;
} else {
checkboxes.style.display = "none";
expanded = false;
}
}
.multiselect {
width: 200px;
}
.selectBox {
positio...
How can I convert ereg expressions to preg in PHP?
...str);
preg_match('(^hello)', $str);
preg_match('{^hello}', $str);
// etc
If your delimiter is found in the regular expression, you have to escape it:
ereg('^/hello', $str);
preg_match('/^\/hello/', $str);
You can easily escape all delimiters and reserved characters in a string by using preg_quo...
What is the point of “final class” in Java?
...of all, I recommend this article: Java: When to create a final class
If they do, when do they use it so I can understand it better and know when to use it.
A final class is simply a class that can't be extended.
(It does not mean that all references to objects of the class would act as if t...
Best Practice: Initialize JUnit class fields in setUp() or at declaration?
...
If you're wondering specifically about the examples in the JUnit FAQ, such as the basic test template, I think the best practice being shown off there is that the class under test should be instantiated in your setUp method (...
What is a database transaction?
... than possible) explanation of a transaction as applied to computing (even if copied from Wikipedia)?
11 Answers
...
Variable name as a string in Javascript
...usfx you can swap out const for let or var and it works just the same. But if you're using a transpiler for the object destructuring in the first place, it probably supports const already.
– SethWhite
Dec 12 '17 at 15:19
...
Retrieve only static fields declared in Java class
...s = new ArrayList<Field>();
for (Field field : declaredFields) {
if (java.lang.reflect.Modifier.isStatic(field.getModifiers())) {
staticFields.add(field);
}
}
share
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improve ...
Install a Windows service using a Windows command prompt?
...
If it is the x64 compiled service, use "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\installutil.exe".
– nme
Feb 23 '16 at 10:10
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