如何将数组的内容输出为逗号分隔的字符串？

Question

I would like to convert an array if IDs, into a string of comma separated values, to use in a MySQL UPDATE query. How would I do this?

Answer 1

implode(',', $array);

Answer 2

记住要逃避值：

'"' . implode('","', array_map('mysql_real_escape_string', $data)) . '"'

Answer 3

Make sure you pass the results through mysql_real_escape_string() before executing your query. This should prevent sql injection if you use implode() as others suggest.

And as nickf mentions, always check to make sure the array isn't empty or null first, and handle those cases. Since you are only dealing with int's, it wouldn't hurt to put some type checking in your assignments, otherwise you'll get sql errors if a string slips in somehow.

Answer 4

Often this type of situation is people building an array from another table for use in a 2nd query.. If this is the case you can use a subquery to accomplish this.

Eg. UPDATE Table SET Column = Value WHERE ID IN ( SELECT ID FROM Table2 WHERE CONDITIONS )

Answer 5

This is probably better if all ids should be numerical. Check that it consists of at least one integer with

$ids = array_filter($ids, 'is_int');
if (!$ids) {
    //no valid ids returned.
    die('or something');
}
$sql .= '(' . implode(',', $ids) . ')';