从php中的mysql查询结果中获取列信息？

Question

I am trying to print out the column headers for any query entered. I have other code that connects to the database and actually prints the results, but I am having trouble with the line

'$result .= $heading->name;'

I keep getting this error:

'Catchable fatal error: Object of class mysqli_result could not be converted to string in...'

Could someone explain what the problem is? According to the php manual this should give me the right information. I am fairly new to php though, so if you improve the code could you please explain how you did it?

I have the following code so far that gets a result from a query:

$result = mysqli_query($conn,$query);
if($result){
    if( mysqli_num_rows($result)>0){
        $columnNo = mysqli_num_fields($result);
        for($i=0;$i<$columnNo;$i++){
            $heading = mysqli_fetch_field_direct($result,$i);
            $result .= $heading->name;
        }
    }
}

Answer 1

$result is an object being used by mysqli. Then you try to append a string onto the end of it.

Just use a different variable name besides $result which will be a string in which you will collect the names of your columns. Or you might save the names in an array like this:

$var[] = $heading->name;

Answer 2

since $result is an object you are using for executing the query, i won't be able to store any other data coming from db. you have to take another variable (say $variable ) to store the data coming from db. Follow the below code:

$result = mysqli_query($conn,$query);
$variable='';  // add this
if($result){
    if( mysqli_num_rows($result)>0){
        $columnNo = mysqli_num_fields($result);
        for($i=0;$i<$columnNo;$i++){
            $heading = mysqli_fetch_field_direct($result,$i);
            $variable .= $heading->name;  //modify here
        }
    }
}

I hope this will solve the issue..