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Difference between Key, Primary Key, Unique Key and Index in MySQL
... A primary key is a column, or a combination of columns, that can uniquely identify a row. It is a special case of unique key. A table can have at most one primary key, but more than one unique key. When you specify a unique key on a column, no two distinct rows in a table can have the same value.
...
Format number to always show 2 decimal places
... / 100).toFixed(2);
Live Demo
var num1 = "1";
document.getElementById('num1').innerHTML = (Math.round(num1 * 100) / 100).toFixed(2);
var num2 = "1.341";
document.getElementById('num2').innerHTML = (Math.round(num2 * 100) / 100).toFixed(2);
var num3 = "1.345";
document.getElementById(...
Flask-SQLalchemy update a row's information
... you're still confused on the differences after reading through there, consider asking another question.
– Mark Hildreth
Jul 15 '11 at 15:36
...
Likelihood of collision using most significant bits of a UUID in Java
If I'm using Long uuid = UUID.randomUUID().getMostSignificantBits() how likely is it to get a collision. It cuts off the least significant bits, so there is a possibility that you run into a collision, right?
...
socket.io and session?
...lashsocket transport in my code.
To make it work, in the express/connect side, I explicitly define the session store so I can use it inside socket:
MemoryStore = require('connect/middleware/session/memory'),
var session_store = new MemoryStore();
app.configure(function () {
app.use(express.sessi...
CSS Pseudo-classes with inline styles
...nk of inline styles as the styles applied to some anonymous super-specific ID selector: those styles only apply to that one very element with the style attribute. (They take precedence over an ID selector in a stylesheet too, if that element has that ID.) Technically it doesn't work like that; this ...
mysql Foreign key constraint is incorrectly formed error
I have two tables, table1 is the parent table with a column ID and table2 with a column IDFromTable1 (not the actual name) when I put a FK on IDFromTable1 to ID in table1 I get the error Foreign key constraint is incorrectly formed error . I would like to delete table 2 record if tab...
Passing Parameters JavaFX FXML
...
class CustomerDialogController {
@FXML private Label customerName;
void initialize() {}
void initData(Customer customer) {
customerName.setText(customer.getName());
}
}
A new FXMLLoader is constructed as shown in the sample code i.e. new FXMLLoader(location). The location is a URL an...
How to convert URL parameters to a JavaScript object?
...answer: https://stackoverflow.com/a/1746566/1194694 there's no spec for deciding what to do with it and each framework can behave differently.
A common use case will be to join the two same values into an array, making the output object into:
{foo: ["first_value", "second_value"]}
This can be a...
Navigation in django
...ad>
<body>
...
{% block nav %}
<ul id="nav">
<li>{% block nav-home %}<a href="{% url home %}">Home</a>{% endblock %}</li>
<li>{% block nav-about %}<a href="{% url about %}">About</a>{% endblo...