Dynamic table column blanking

Tbull

Have results of query passed through PHP to MySQL which is returned from several hundred rows grouped that gets displayed as a table like Table A (sorry about the line-up):

Table A

What I need/want is to have the display like Table B, the ...... are just place holders to show approximate alignment for a couple of the "|Topicxx columns :

Table B

The php I am using to return the results in Table A is basic and follows:

PHP

// layout table header
echo "<table border =1>\n";
echo "<tr bgcolor=\"#CCFFCC\" align = center>\n";
echo "<td>            </td>\n";

for ($i=0; $i<$number_cols; $i++)
{
echo "<th>" . mysql_field_name($result, $i). "</th>\n";
}
echo "</tr>\n"; //end layout table header

// layout table body
while ($row = mysql_fetch_row($result))
{
$row_color = ($row_count % 2) ? $color1 : $color2;
echo "<tr align = left bgcolor=\"$row_color\">\n";
echo "<td bgcolor=\"$row_color\"> </td>";
for ($i=0; $i<$number_cols; $i++)
{
echo "<td>";
if (!isset($row[$i]))
{echo "NULL";}
else
{echo $row[$i];}
echo "</td>\n";
}
$row_count++;
echo "</tr>\n";
}

echo "</table>";

I would like to keep the table construct dynamic, as different queries can return different numbers of columns.

Suggestions or guidance are greatly appreciated I have been in and out of the manual, code snippets, etc. I am certain there is some simple construct that will allow me to space file, and dynamically display to the next row sets. No success to this juncture.

Thanks,
Tbull

archangel_617b

Just a note: Use [ php ] or [ code ] tags around any code your provide to make it mildly readable, please.

This is easy-peasy... Kinda. Way I'd do it is to create an array called something like $DUPES.

Find the number of fields to be handled by the $DUPES array using [man]mysql_num_fields/man. For each field in the result set, there will be a matching element in $DUPES.

As you iterate through each row, check the current value against the corresponding $DUPES value (the first time will never match since only NULLs are in the $DUPES).

IF the current data value matches the DUPES value, do not display it and move on.
ELSE store the new value and print it.

Not too clear?

For example, mysql_num_fields will return 4.
Now you create an empty array $DUPES
You have an outer loop to fetch each row.
You have an inner loop that iterates through each field (from 0 to 3 in this case)
In the inner loop, you check $DUPES[$i] against $rows[$i].
Find a match?

Move on. (print an empty cell)
Else?
$DUPES[$i] = $row[$i]
output $row[$i]

Sound good to you or did I mis-understand the problem?

Tbull

Will examine the logic to see if my feeble mind comprehends the flow. It seems that my problem is similar in construct to the response you provided in "Grouping Under DATEs".

I admit to being a bit lost in what you have proposed as creating another array and comparing the two. Will dig at this.

If I understand correctly the Dupes array is created from the existing results set? Then build another loop for comparison within the existing while.

Thanks,
Tbull

PS: I thought I had indicated the PHP code. Is there a better/clearer way. Thanks again.

archangel_617b

Give a man a fish, he'll eat for a meal. Teach a man to fish...

Okay, what DUPES is doing is just storing the last value used. If the value does not change, then you do not need to print it, otherwise you print the new value and store that. so...

Lets say you have simple table for demonstration. Two fields 'letter' and 'number'. You have some data that looks like this:

Table:
a | 1
a | 2
a | 3
b | 1
b | 2
b | 3

So, I assume the output you want is:

Table:
a | 1
| 2
| 3
b | 1
| 2
| 3

So.... The first time DUPES is exmined in the loop, it is empty:
$DUPES = array(0 => , 1 => );

The first row you fetch looks like:
$row = array(0 => 'a', 1 => 1);

You can iterate through each column. Now, the first comparison, you check $DUPES[0] against $row[0]. Since 'a' != NULL, you print 'a' and store 'a' in DUPES. Same with the next colum.

Now the second time trhough the loop, you get:
$DUPES = array(0 => 'a', 1 => 1);
$row = array(0 => 'a', 1 => 2);

As you check the first colum, it is the same, so you print an empty cell whereas the second colum you find 1 != 2 so you print that and update DUPES.

So DUPES is just a copy of the last row of data. You can use it to determine if you have changing information (which needs to be printed) or if you have static information (which you only need a place-holder for). In this manner, 'a' is printed the first time only and nothing else is printed in that column until the first 'b' is encountered.

Tbull

archangel_617b,

Thank you for your guidance and patience. Your suggestion caused me to rethink the strategy. Using a variable variable I can easily and with little overhead check the contents of the column(s) and output a blank table cell. I have included the code from the table generator here.

[code=php]

$flyRowValHOLD =" "; // set initial value

// layout table header
echo "<table border =1>\n";
echo "<tr align = center1>\n";
for ($i=0; $i<$number_cols; $i++)
{
echo "<th>" . mysql_field_name($result, $i). "</th>\n";
}
echo "</tr>\n"; //end layout table header
while ($row = mysql_fetch_row($result))
{
$row_color = ($row_count % 2) ? $color1 : $color2;
echo "<tr align = left bgcolor=\"$row_color\">\n";
for ($i=0; $i<$number_cols; $i++)
{
$fldaname = "flyRowVal$i";
$$fldaname = "$row[$i]";
echo "<td>";
if ($flyRowVal0 != $flyRowValHOLD)
{
echo "   ".$row[$i];
$flyRowValHOLD = $flyRowVal0;
}
else
if (!isset($row[$i])) //tests for null value
{echo "NULL";}
else
if ($i !=0)
{echo $row[$i];}
echo "</td>\n";
}
$row_count++;
echo "</tr>\n";
}
echo "</table>";

=========================================

Thanks and I sincerely appreciate your contribution.

Tbull 😃

Tbull

Duh,... really thick. Just figured out the php thing.

$flyRowValHOLD =" "; // set initial value
// layout table header
echo "<table border =1>\n";
echo "<tr align = center1>\n";
for ($i=0; $i<$number_cols; $i++)
  {
   echo "<th>" . mysql_field_name($result, $i). "</th>\n";
  }
echo "</tr>\n"; //end layout table header
while ($row = mysql_fetch_row($result))
{
  $row_color = ($row_count % 2) ? $color1 : $color2;
  echo "<tr align = left bgcolor=\"$row_color\">\n";
  for ($i=0; $i<$number_cols; $i++)
    {
       $fldaname = "flyRowVal$i";
       $$fldaname = "$row[$i]";
       echo "<td>";
       if ($flyRowVal0 != $flyRowValHOLD)
         {
           echo "&nbsp;&nbsp;   ".$row[$i];
           $flyRowValHOLD = $flyRowVal0;
         }
     else
 		  if (!isset($row[$i])) //tests for null value
		     {echo "NULL";}
 	  else
         if ($i !=0)
         {echo $row[$i];}
     echo "</td>\n";
    }
     $row_count++;
  echo "</tr>\n";
}
echo "</table>";
echo "<hr>\n";

Thanks to all.
Tbull