How to display group_concat result seperately in html table cell?

问题

On my previous question How to group array value duplicate and customize the display of the results of the array in html table? which has not been answered yet, I opt in other way to display the 5 rows only.

This is the database:

 lid   class_id   class         Q1-2      Q3-4      total   item_group  
-----  -------    -----         -----    -----      -----   ----------
   1     73       Leader        5000      50000     10000      33
   1     77       Consultant    4000      4000      8000       33
   1     83       Coordinator   3000      3000      6000       33
   2     73       Leader        10000     10000     20000      33
   2     76       Staff         4000      4000      8000       33
   2     77       Consultant    5000      50000     10000      33
   3     73       Leader        15000     15000     30000      33
   3     78       Team Leader   4000      4000      8000       33

Here is the SQL query that I used:

$sql = "SELECT *, group_concat(AZ.lid) as lids, group_concat(AZ.total) AS totals FROM (
    SELECT * FROM view_items WHERE lid='1' 
    UNION 
    SELECT * FROM view_items WHERE lid='2' 
    UNION 
    SELECT * FROM view_items WHERE lid='3' 
) AS AZ WHERE item_group='33' GROUP BY class_id";

This is the SQL result:

class id    class        lid    Q1-2    Q3-4     lids    totals             item_group
---------   -----       ------  -----   -----    -----   ------             ----------
   73      Leader         1     5000    5000     1,2,3   10000,20000,30000     33
   77      Consultant     1     4000    4000     1,2     8000,10000            33
   83      Coordinator    1     3000    3000     1       6000                  33
   76      Staff          2                      2       8000                  33
   78      Team Leader    3                      3       8000                  33

$proj_lid->lid is equals to 1 (Displayed in the P1 column only)

$row->lid is equals to 1 (Displayed in the P1 column only)

$limit is 3 (The count of P's)

This is the html table part:

<?php
 for($iy=1; $iy<=$limit; $iy++){                    
    $sql_lid =  "SELECT * FROM view_items WHERE lid='$iy' GROUP BY lib_id ORDER BY lid ASC";
    $query_lid = $this->db->prepare($sql_lid);
    $query_lid->execute();
    $res=$query_lid->fetch();   
    $lids = $res->lid;
    $lid_arr[] = $lids ;    
    $sql_arr = "";  
    if($iy==1) $sql_arr .= "SELECT *, group_concat(AZ.lid) as lids, group_concat(AZ.total) AS totals FROM (";   
    $sql_arr.="SELECT * FROM view_items WHERE lid='$lids'";   
    if($iy!=$limit) $sql_arr .= " UNION ";      
    if($iy==$limit)  $sql_arr.=" ) AS AZ WHERE item_group='33' GROUP BY class_id";
    $sqlArr[] = $sql_arr;                               
}
 $sql = implode("",$sqlArr);        
 $query = $this->db->prepare($sql);
 $query = $this->db->prepare($sql);
 $query->execute();
 $result = $query->fetchAll();
 foreach($result as $row){  
    if($row->item_group == "33"){                       
        $q1 = ($row->q1-2)
        $q3 = ($row->q3-4) 
        $total = $q1 + $q3;
?>
<tr>            
    <td><?php echo $row->class; ?></td>             
    <td><?php if($q1 != 0 && $proj_li->lid == $row->lid){ echo ($q1 < 0 ? "(".number_format(abs($q1),2).")" : number_format($q1,2));} else{ echo "-";} ?> </td>
    <td><?php if($q3 != 0 && $proj_lid->lid == $row->lid ){ echo ($q3 < 0 ? "(".number_format(abs($q3),2).")" : number_format($q3,2));} else{ echo "-";} ?> </td>               
    <td><?php if($total != 0 && $proj_lid->lid == $row->lid ){ echo ($total < 0 ? "(".number_format(abs($total),2).")" : number_format($total,2));} else{ echo "-";} ?> </td>   
<?php   
    $totals = explode(", ", $row->totals);  
    foreach ($totals as $rowstotals) {      
    }
    for($i = 1; $i <= $limit; $i++){                    
    if ($i != $proj_lid->lid && $proJ-lid->lid < $i){
?>
      <td><?php if($rowstotals != 0){ echo ($rowstotals < 0 ? "(".number_format(abs($rowstotals),2).")" : number_format($rowstotals,2));} else{ echo "-";}?></td>   
<?php
    } else{ } 
   } 
  }  
 } 
?>
</tr>

I managed to display the expected output
Expected Output (with 5 rows only, no duplicate class id)

But another problem occurred in displaying the group_concat values separately. I need the values in P2 and P3 to display only one result from the group_concat.

This should be the expected output

UPDATE: I found (maybe) a similar output to what I want to do (forgot where I saw this link) Link

回答1:

This is what I had in mind:

SELECT lid, class_id,class, `Q1-2`,`Q3-4`,total,
       CASE WHEN COUNT(*)>=2 THEN SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(total ORDER BY lid ASC SEPARATOR ' '),' ',2),' ',-1) END AS P2,
       CASE WHEN COUNT(*)>=3 THEN SUBSTRING_INDEX(SUBSTRING_INDEX(GROUP_CONCAT(total ORDER BY lid ASC SEPARATOR ' '),' ',3),' ',-1) END AS P3
      FROM (SELECT * FROM view_items WHERE lid='1' UNION 
            SELECT * FROM view_items WHERE lid='2' UNION 
            SELECT * FROM view_items WHERE lid='3' ) AS AZ 
      WHERE item_group='33'
GROUP BY class_id ORDER BY lid ASC;

I use SUBSTRING_INDEX function twice on a GROUP_CONCAT value that is 2 or more but in this example I stopped at 3 count. I also added ORDER BY lid ASC in GROUP_CONCAT to make sure that it will return value ordered by lid.

来源：https://stackoverflow.com/questions/56322476/how-to-display-group-concat-result-seperately-in-html-table-cell

标签

php

mysql

group-concat