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What are DDL and DML?
...als with data
manipulation, and includes most common SQL statements such SELECT,
INSERT, UPDATE, DELETE etc, and it is used to store, modify, retrieve,
delete and update data in database.
SELECT – retrieve data from the a database
INSERT – insert data into a table
UPDATE – up...
Why is “except: pass” a bad programming practice?
...eption.
For example, when you ask for the user to input a number, you can convert the input using int() which might raise a ValueError. You can easily recover that by simply asking the user to try it again, so catching the ValueError and prompting the user again would be an appropriate plan. A diff...
date format yyyy-MM-ddTHH:mm:ssZ
...
One option could be converting DateTime to ToUniversalTime() before converting to string using "o" format. For example,
var dt = DateTime.Now.ToUniversalTime();
Console.WriteLine(dt.ToString("o"));
It will output:
2016-01-31T20:16:01.909234...
PHP - iterate on string characters
...
Step 1: convert the string to an array using the str_split function
$array = str_split($your_string);
Step 2: loop through the newly created array
foreach ($array as $char) {
echo $char;
}
You can check the PHP docs for more in...
SQL query return data from multiple tables
...rows affected (0.00 sec)
Records: 5 Duplicates: 0 Warnings: 0
mysql> select * from colors;
+----+-------+----------+
| id | color | paint |
+----+-------+----------+
| 1 | Red | Metallic |
| 2 | Green | Gloss |
| 3 | Blue | Metallic |
| 4 | White | Gloss |
| 5 | Black | Gloss ...
WPF ListView turn off selection
...
Per Martin Konicek's comment, to fully disable the selection of the items in the simplest manner:
<ListView>
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="Focusable" Value="false"/>
&...
The tilde operator in C
...
@MarcusJ Yes, one's complement works for converting signed to unsigned (signed->unsigned). (Note though it's easier to just assign the value to a variable declared differently and lett the compiler worry about it.) But it does not work the other way around (unsig...
Validate that a string is a positive integer
... but if that results in a blank string, restores a single 0.
Number(str): Convert str to a number; the number may well have a fractional portion, or may be NaN.
Math.floor: Truncate the number (chops off any fractional portion).
String(...): Converts the result back into a normal decimal string. Fo...
parseInt vs unary plus, when to use which?
...
The unary + on the other hand will return NaN if the entire string is non-convertible to a number.
parseInt('2a',10) === 2; //true
parseFloat('2a') === 2; //true
isNaN(+'2a'); //true
As seen in the comment of @Alex K., parseInt and parseFloat will parse by character. This means ...
How to get distinct values for non-key column fields in Laravel?
...lder you can do it this way:
$users = DB::table('users')
->select('id','name', 'email')
->groupBy('name')
->get();
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