Can you 'exit' a loop in PHP?

Question 1

I have a loop that is doing some error checking in my PHP code. Originally it looked something like this...

foreach($results as $result) {
    if (!$condition) {
        $halt = true;
        ErrorHandler::addErrorToStack('Unexpected result.');
    }

    doSomething();
 }

if (!$halt) {
    // do what I want cos I know there was no error
}

This works all well and good, but it is still looping through despite after one error it needn't. Is there a way to escape the loop?

Question 2

You are looking for the break statement.

$arr = array('one', 'two', 'three', 'four', 'stop', 'five');
while (list(, $val) = each($arr)) {
    if ($val == 'stop') {
        break;    /* You could also write 'break 1;' here. */
    }
    echo "$val<br />n";
}

Question 3

No PHP is needed. You can do it with pure MySQL code only.

Create table/insert table

CREATE TABLE HugeTable
    (`Column1` VARCHAR(11), `Column2` VARCHAR(11), `Column3` VARCHAR(11))
;

INSERT INTO HugeTable
    (`Column1`, `Column2`, `Column3`)
VALUES
    ('Data1;Data2', 'Data3;Data4', 'Data5;Data6')
; 

CREATE TABLE NewTable
   (`Column1` VARCHAR(11), `Column2` VARCHAR(11), `Column3` VARCHAR(11))
;

First we need MySQL to generate numbers. This MySQL code generates 1 to 100. So the final query will support up to 100 separated values.

Query

SELECT 
 @row := @row + 1 AS ROW
FROM (
  SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9
) row1
CROSS JOIN (
  SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9
) row2
CROSS JOIN (
  SELECT @row := 0 
) init_user_params

Result

Now we can look at a method to separate on the ; delimiter. We can use nested SUBSTRING_INDEX functions for that

Query

SELECT SUBSTRING_INDEX(SUBSTRING_INDEX('Data1;Data2', ';', 1), ';', -1) AS DATA

Result

data    
--------
Data1

You can see only the first word is returned if we want the second word we can use

Query

SELECT SUBSTRING_INDEX(SUBSTRING_INDEX('Data1;Data2', ';', 2), ';', -1) AS DATA

Result

data    
--------
Data2

Now we combine the number generator and the SUBSTRING_INDEX to generate the data

Query

SELECT 
  DISTINCT
   SUBSTRING_INDEX(SUBSTRING_INDEX(Column1, ';', rows.row), ';', -1) Column1
 , SUBSTRING_INDEX(SUBSTRING_INDEX(Column2, ';', rows.row), ';', -1) Column2
 , SUBSTRING_INDEX(SUBSTRING_INDEX(Column3, ';', rows.row), ';', -1) Column3
FROM (
  SELECT 
   @row := @row + 1 AS ROW
  FROM (
    SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9
  ) row1
  CROSS JOIN (
    SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9
  ) row2  
  CROSS JOIN (
    SELECT @row := 0 
  ) init_user_params
)
 ROWS
CROSS JOIN 
 HugeTable

Result

Column1  Column2  Column3  
-------  -------  ---------
Data1    Data3    Data5    
Data2    Data4    Data6

Query NewTable

INSERT INTO 
  NewTable
SELECT 
  DISTINCT
   SUBSTRING_INDEX(SUBSTRING_INDEX(Column1, ';', rows.row), ';', -1) Column1
 , SUBSTRING_INDEX(SUBSTRING_INDEX(Column2, ';', rows.row), ';', -1) Column2
 , SUBSTRING_INDEX(SUBSTRING_INDEX(Column3, ';', rows.row), ';', -1) Column3
FROM (
  SELECT 
   @row := @row + 1 AS ROW
  FROM (
    SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9
  ) row1
  CROSS JOIN (
    SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9
  ) row2  
  CROSS JOIN (
    SELECT @row := 0 
  ) init_user_params
)
 ROWS
CROSS JOIN 
 HugeTable

Query

SELECT * FROM NewTable

Result

Column1  Column2  Column3  
-------  -------  ---------
Data1    Data3    Data5    
Data2    Data4    Data6

Question 4

The reason why your script is not printing EBU, Belgacum sa lies in this part:

while($row = $sth->fetch()) {
    array_push($dates,new DateTime($row['date']));
    $name = $row['name'];
    $company = $row['company'];
}

While the date values are pushed to an array, $name and $company are overwritten by each new line.

Further, I think your script overcomplicates the issue. How about this?

    $output = '';
    $list = array();
    $lastitem = $lastdate = null;
    $query = 'SELECT name, company, date FROM project GROUP BY date ORDER BY date, name, company';
    $sth   = $dbh->prepare($query);
    $sth->execute();
    if($sth->rowCount() > 0) {
            $i = 0;
        while($row = $sth->fetch()) {
                $date = new DateTime($row['date']);
                $item = array(
                    'date' => array(),
                    'name' => $row['name'],
                    'company' => $row['company'],
                );
                if ($item === $lastitem && $date->diff($lastdate)->days === 1) {
                    $list[$i-1]['date']['end'] = $date;
                }
                else {
                    $list[$i] = $item;
                    $list[$i]['date']['start'] = $date;


                    $lastitem = $item;
                    $lastdate = $date;
                    $i++;
                }
        }
    }
    if (count($list)) {
            $output .= '<ul>';
    }
    foreach ($list AS $item) {
            $output .= '<li>' . $item['name'] . ', ' . $item['company'] . ' - ' . $item['date']['start']->format('d/m/Y');
            $output .= isset($item['date']['end']) ? ' tot ' . $item['date']['end']->format('d/m/Y') : '';
            $output .= '</li>';
    }
    if (count($list)) {
            $output .= '</ul>';
    }

Question 5

until passwd
do
  echo "Try again"
done

or

while ! passwd
do
  echo "Try again"
done

Question 6

It will include the file ten times.

If that's a problem, you could use include_once

Can you 'exit' a loop in PHP?

Answers

php,loops