Convert multiple square bracket values into array php

Question

I've got the following data in a db

[508] [blah-blah-blah] Random Text
[510] [hello-hello-hello] More random text
[542] [stuff-stuff-stuff] Even more text

This is in quite a lot of db cells. The whole block of text is in a cell and each row of the text is separated by a carriage return.

Ideally i want the number in the first square bracket on each line into array values. The data i want to end up with is:

array(508,510,542)

More importantly, i want to see how to efficiently get that first data structure into a array. i feel like there should be a simple efficient way to use it, but, aside from some really complex regex i cannot see how to do it :(

Any help would be magical!

Answer 1

In PHP you can match the numbers using lookarounds for the literal brackets using preg_match_all()

<?php

    $string = '[508] [blah-blah-blah] Random Text
    [510] [hello-hello-hello] More random text
    [542] [stuff-stuff-stuff] Even more text';
    preg_match_all ('!(?<=\[)([0-9]+)(?=\])!',$string,$matches);
    print_r($matches[0]);

?>

Output

Array
(
    [0] => 508
    [1] => 510
    [2] => 542
)

To handle all of the records from the database, you would do something like this:

    $result = mysqli_query($sql);
$records = array(); 
while ($row = mysqli_fetch_array($result)){


        preg_match_all ('!(?<=\[)([0-9]+)(?=\])!',$row['my_text_field'],$matches);
        foreach($matches[0] as $value){     
        $records[]=$value;
        }

}

print_r($records);      

Answer 2

Given that your numbers always appear at the start of each line, the expression is pretty simple:

$input = <<<EOM
[508] [blah-blah-blah] Random Text
[510] [hello-hello-hello] More random text
[542] [stuff-stuff-stuff] Even more text
EOM;

preg_match_all('/^\[(\d+)\]/m', $input, $matches);
print_r($matches[1]);

I'm using the /m modifier to enable multiline mode, causing ^ to match the start of each line.

Answer 3

From the DB directly:

mysqli_query("SELECT SUBSTRING_INDEX(SUBSTRING(your_column_name, 1), ']', 1) FROM tablename");

SUBSTRING(str, pos) works like substr() would in php in that it extract a slice of the original string.

SUBSTRING(your_column_name, 1) means copy "your_column_name" starting from index 1 to the end.

[508] [blah-blah-blah] Random Text
Becomes
508] [blah-blah-blah] Random Text

SUBSTRING_INDEX(str, C, X) copy the entire string str until the Xth occurence of character C

SUBSTRING_INDEX(str, ']', 1) means copy the the entire string until the first occurence of ]

508] [blah-blah-blah] Random Text

Becomes

508