2.3
will be rounded to 2 and the second 2.5
becomes 3SELECT
ROUND(2.3),
ROUND(2.5)
php artisan make:component ComponentName
creates ComponentName.blade.php
inside resources/view/components
and controller ComponentName.php
inside App\View\Component
directory
you can render component by x-
syntax <x-component-name />
pass variables to components
use var-name=
for normal strings and use :var-name=
for variables
<x-component-name var-name="normal string" :var-name2="$some_variable"/>
make sure to use kebab-case
as html attribute names and camelCase
inside constructor argument
and inside component controller file ComponentName.php
namespace App\View\Components;
use Illuminate\View\Component;
class ComponentName extends Component
{
public $varName1;
public $varName2;
public function __construct($varName1, $varName2)
{
$this->varName1 = $varName1;
$this->varName2 = $varName2;
}
public function customFunction($last)
{
return [1, 2, 3, 4, 5, 6, 7, $last]; // or data from db for example
}
/**
* Get the view / contents that represent the component.
*
* @return \Illuminate\View\View|\Closure|string
*/
public function render()
{
return view('components.component_name');
}
}
inside ComponentName.blade.php
we can retrieve these variables like so
<div class="component-class">
<div>{{$varName1}}</div>
<div>{{$varName2}}</div>
@foreach($customFunction('last line') as $line)
<h1>{{$line}}</h1>
@endforeach
</div>
quotation marks
, then the parameter is going to be interpreted as a column value.
Converts a string or column value to UPPER-CASE
SELECT
UPPER(first_name),
UPPER('Converts a string or column value to UPPER-CASE')
FROM students
Converts a string or column value to lower-case
SELECT
LOWER(first_name),
LOWER('Converts a string or column value to lower-case')
FROM students
Joins strings and columns togetherSELECT
CONCAT(first_name, ' ', 'joins', ' ', 'strings', ' ', 'and', ' ', 'columns')
FROM students
The function LENGTH
Returns the length (in bytes) SELECT
id,
first_name,
LENGTH(first_name) first_name_length
FROM students
Note: Each Georgian letter takes three bytes
The function is similar to CONCAT
where WS
means - With Separator.
The first parameter is the separator between each one of the additional fields, that we pass as next parametersSELECT
CONCAT_WS(' - ', first_name, 'joins', 'strings', 'and', 'columns', 'with', 'separator')
FROM students
The function TRIM
removes leading and trailing spacesSELECT
LENGTH(' text ') length,
LENGTH(TRIM(' text ')) length_with_trim
The function RTRIM
removes trailing spaces (removes spaces from the end)SELECT
LENGTH(' text ') length,
LENGTH(RTRIM(' text ')) length_with_right_trim
The function LTRIM
remove leading spaces (removes spaces from the beginning)SELECT
LENGTH(' text ') length,
LENGTH(LTRIM(' text ')) length_with_left_trim
The function LEFT
returns leftmost characters. In this case 5 characters because we pass 5 as second parameterSELECT
LEFT(first_name, 5) AS 'five leftmost characters'
FROM students
The function RPAD
appends string (third parameter) the specified number of times (second parameter) to the first parameter.
In this example each one of the student's last name that is less than 10 characters long, is filled with -
SELECT
RPAD(first_name, 10, '-') AS 'student name'
FROM students
Complete list of string functions on the official documentation: https://dev.mysql.com/doc/refman/8.0/en/string-functions.htmlROUND
rounds the passed value using standard Math rules.
The first argument 2.3
will be rounded to 2 and the second 2.5
becomes 3SELECT
ROUND(2.3),
ROUND(2.5)
Function FLOOR
rounds the argument down to the greater integer less then the decimal argument.
Both of the arguments will be rounded down to 2
SELECT
FLOOR(2.3),
FLOOR(2.8)
Function CEIL
rounds the number up to the lowest integer value greater than the passed decimal argument.
Both of the arguments will be rounded to 3
SELECT
CEIL(2.3),
CEIL(2.8)
Function RADIANS
converts degrees to radians.
90
degrees converted to radians gives us half of PI
: 1.5707963267948966
.
180
degrees converted to radians gives us PI
: 3.141592653589793
.SELECT
RADIANS(90),
RADIANS(180)
Function DEGREES
converts radians back to degrees.
Half of PI
radians 1.5707963267948966
converted to degrees gives us 90
degrees.
PI
: 3.141592653589793
radians converted to degrees gives us 180
degrees.SELECT
DEGREES(1.5707963267948966),
DEGREES(3.141592653589793)
These two functions RADIANS
and DEGREES
are opposite to each other.
180
degrees converted to radians gives us PI
: 3.141592653589793
PI
: 3.141592653589793
radians converted to degrees gives us 180
degrees.SELECT
RADIANS(180),
DEGREES(3.141592653589793)
Function POWER
raises the first argument to the power of another argument.
The code below returns 16
because 2
to the power of 4
is 16
SELECT
POWER(2, 4)
Note: POW
and POWER
are the aliases for the same command
The function CONV
converts the first argument from one number system (the second argument) to another (the third argument)
Converts 5
from 10
base system to 2
SELECT
CONV(5, 10, 2)
Complete list of mathematical functions on the official documentation: https://dev.mysql.com/doc/refman/8.0/en/mathematical-functions.htmlREPLACE
statement updates the listed columns if primary key (one of the listed columns) already exists. Otherwise inserts as a new recordREPLACE INTO students (id, first_name, points)
VALUES (41, 'ილიკო', 147)
Similar to the REPLACE INTO
statement is ON DUPLICATE KEY
.
The only difference is that on duplicate key it updates only the listed columns but omitted values stays the sameINSERT INTO students (id, first_name, points)
VALUES (41, 'გიორგი', 149)
ON DUPLICATE KEY
UPDATE first_name = 'გიორგი', points = 123
Note 1
: If primary key is not listed, it will insert the record, but if the primary key is one of the listed columns, it will update the specified row that matches the primary key.
Note 2
: If the primary key exists, all the other omitted columns will get the default values after updating the record.RPAD
appends string (third parameter) the specified number of times (second parameter) to the first parameter.
In this example each one of the student's last name that is less than 10 characters long, is filled with -
SELECT
RPAD(first_name, 10, '-') AS 'student name'
FROM students
LEFT
returns leftmost characters. In this case 5 characters because we pass 5 as second parameterSELECT
LEFT(first_name, 5) AS 'five leftmost characters'
FROM students
LTRIM
remove leading spaces (removes spaces from the beginning)SELECT
LENGTH(' text ') length,
LENGTH(LTRIM(' text ')) length_with_left_trim
TRIM
removes leading and trailing spacesSELECT
LENGTH(' text ') length,
LENGTH(TRIM(' text ')) length_with_trim