PHP Implode not working with mysql_query

Question

So I have two arrays, $gDatabaseKeyNames (list of column names) and $gDatabaseKeyValues (a list of variable names containing values from a script). The variable names are generated dynamically so I keep track of them for an insert.

Rather than listing all of the columns and value variables, I tried this

$cols = implode(", ", array_values($gDatabaseKeyNames));
$vals = implode(", ", array_values($gDatabaseKeyValues));

$query = "INSERT INTO pings (survey_id, $cols) VALUES ('$surveyID', $vals)";                              
mysql_query ($query) or die(mysql_error());

But none of my actual values show up in the database (they are inserted as 0s - all my columns are numeric).

If I echo $query, I see this, which is the correct formatting:

INSERT INTO pings (survey_id, latitude, longitude, pingTimestamp) VALUES ('15', '$Dlatitude', '$Dlongitude', FROM_UNIXTIME('$DtimeStamp'))

However, if I change $query to

$query = INSERT INTO pings (survey_id, latitude, longitude, pingTimestamp) VALUES ('$surveyID', '$Dlatitude', '$Dlongitude', FROM_UNIXTIME('$DtimeStamp'));

It works perfectly!

Why isn't PHP interpreting the variables in the implode? How can I fix this?

Marc B · Accepted Answer · 2011-09-08 17:23:45Z

1

I suspect that $cols has the literal value '$Dlatitude', '$Dlongitude', etc.... PHP does not "double-interpolate" strings. It'll replace $cols with its values, but will NOT replace $Dlatitude with that variable's value. In other words, you're literally inserting some strings-that-look-like-PHP-variable-names into your numeric fields.

What is in the $gDatabaseKeyValues/Names arrays?

answered Sep 8, 2011 at 17:23

Marc B

362k44 gold badges433 silver badges508 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

bld Over a year ago

$gDatabaseKeyValues = ("latitude", "longitude", ..) $gDatabaseKeyNames = ("'$Dlatitude'", "'$Dlongitude'", ..)

Marc B Over a year ago

Remove the quotes from around the $Dxxx vars, so their VALUES go into the array, not their names.

Madara's Ghost · Accepted Answer · 2011-09-08 17:23:13Z

0

It's probably caused because of string/number problems. You should consider changing the database engine (Consider PDO) and use prepared statements to bind the parameters to your query the right way.

answered Sep 8, 2011 at 17:23

Madara's Ghost

176k52 gold badges274 silver badges314 bronze badges

Collectives™ on Stack Overflow

PHP Implode not working with mysql_query

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related