CODEWITHSUNDEEP
jqueryjquery-pluginsdatatables
Codded
Codded

Reputation: 1256

Datatables server-side processing INNER JOIN or multiple tables

Below is my code without server-side processing but as it produces many rows and will grow considerably I need to use server-side processing.

DB Tables (not all fields included but these are the ones i want and the fields to INNER JOIN):

course_modules -       id (pk), course(course.id), module(module.id), added(UNIXTIMESTAMP)
course -               id (pk), category(course_categories.id), fullname(text)
course_categories-     id (pk), name(text)
modules-               id (pk), name(text)

I want to be able to display the UNIXTIMESTAMP as date('d/m/Y');

Would this work for the INNER JOIN

$sQuery = "
    SELECT SQL_CALC_FOUND_ROWS ".str_replace(" , ", " ", implode(", ", $aColumns))."
    FROM   $sTable 
    INNER JOIN modules ON $sTable.module = modules.id 
    INNER JOIN course ON $sTable.course = course.id 
    INNER JOIN course_categories ON course.category = course_categories.id
    $sWhere
    $sOrder
    $sLimit
";

Original php version without server-side processing:

$mods = get_records_sql("SELECT * FROM {$CFG->prefix}course_modules");

foreach ($mods as $mod)
    {

    $thecourse = get_record('course','id',$mod->course); 
    $themodule = get_record('modules','id',$mod->module); 
    $thecat = get_record('course_categories','id',$thecourse->category); 


    echo '<tr>'; 
    echo '<td>'.$thecat->name.'</td>'; 
    echo '<td>'.$thecourse->fullname.'</td>'; 
    echo '<td>'.$themodule->name.'</td>'; 
    echo '<td>';
    echo date('d/m/Y', $mod->added);
    echo'</td>'; 
    echo '</tr>'; 
    }

I have server-side processing woking fine with my datatables but without linking to the other tables. This table only returns IDs and I want to be able to get the value from another table as demonstrated above.

Do I need to use an innner join? If so how can I incorporate with server_processing.php script: I used this one: http://datatables.net/release-datatables/examples/data_sources/server_side.html

Or can I incorporate my above method within server_processing.php.

Any guidance would be greatly appreciated. Thanks in advance.

Upvotes: 3

Views: 11740

Answers (2)

Codded
Codded

Reputation: 1256

Answer to the question: Problem was had 2 column names the same so i used alises in the SQL query. Also did not use INNER JOIN.

Columns array using the alias names and column names:

$aColumns = array( 'catname', 'fullname', 'modulename', 'added');

The SQL query for the 4 tables:

$sQuery = "
    SELECT mdl_course.fullname, mdl_modules.name AS modulename, mdl_course_categories.name AS catname, mdl_course_modules.added
    FROM  mdl_course_modules, mdl_modules, mdl_course, mdl_course_categories
    WHERE mdl_course_modules.module = mdl_modules.id AND mdl_course_modules.course = mdl_course.id AND mdl_course.category = mdl_course_categories.id
    $sOrder
    $sLimit
";
$rResult = mysql_query( $sQuery, $gaSql['link'] ) or die(mysql_error());

Upvotes: 3

Nicola Peluchetti
Nicola Peluchetti

Reputation: 76910

Yes i think that you should use an inner join (but i need more details about the tables to write the exact query) and then you mustmodify the sql here

  $sQuery = "
    SELECT SQL_CALC_FOUND_ROWS ".str_replace(" , ", " ", implode(", ", $aColumns))."
    FROM   $sTable
    $sWhere
    $sOrder
    $sLimit
";
$rResult = mysql_query( $sQuery, $gaSql['link'] ) or die(mysql_error());

EDIT - to log the query do

$filename = __DIR__.DIRECTORY_SEPARATOR."logging.txt";

file_put_contents($filename, $sQuery, FILE_APPEND);

you should have a logging.txt file in the same directory of the script

Upvotes: 2

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