php - What is the best approach to sort MySQL table rows by user choice? -


suppose have mysql table (id , name) , drag-and-drop-enabled list view of table. user drags 90th row , places on 10th row. best approach keep new sorting?

  • i not mean keep sorting every use separately
  • the html/javascript not problem

i have seen programmers add weight column table, setting lower number upper in table. in example 1 100. the problem in case of above example (90 10) updating 81 rows required. 90 changes 10 , each 10 89 increments. efficient in mysql? there better solution?
way maybe saving new order string in table, but in case lose mysql sorting in retrieval phase!

i remember when learned trie tree structure in university indexing tool, said wow! when took advantage of every single bit of byte, 1.5 gb of pure text data stored in less 500kb!!! right still search find better answer!

even programming languages when updating indexes array had object added in occupied index adds 1 each index.

you're going have end updating index every single row.

the cleanest way (where people non trivial table of course):

update people set index = index + 1 index between $newindex , $oldindex;

depending on database, between might include or exclude high , low bound numbers. make sure know how treats them!


Comments

Post a Comment

Popular posts from this blog

apache - Remove .php and add trailing slash in url using htaccess not loading css -

i have add following code htaccess file removing .php extension , add trailing slash urls. worked fine reduced page loading speed , css code not loading @ all. pages ugly. please help rewriteengine on rewritebase / ## hide .php extension snippet # externally redirect /dir/foo.php /dir/foo rewritecond %{the_request} ^[a-z]{3,}\s([^.]+)\.php [nc] rewriterule ^ %1/ [r,l] # add trailing slash rewritecond %{request_filename} !-f rewritecond %{request_uri} !/$ rewriterule . %{request_uri}/ [l,r=301] # internally forward /dir/foo /dir/foo.php rewritecond %{request_filename} !-d rewritecond %{request_filename}.php -f rewriterule ^(.*?)/?$ $1.php [l] we can rewrite urls using .htaccess files. before writing in .htaccess files need verify kind of server using. can check server adding a <?php phpinfo(); ?> in php page. ensure mod_rewrite module enabled in apache server. can identified checking phpinfo included page. common methods used url rewriting follows ...
Read more

javascript - jQuery show full size image on click -

pretty self explanatory not workking . i want display full image when user click on image... yes know there tons of plugins but i want keep simple. any idea ? css : .full { display: none; width: 500px; height: 500px; margin-left: 100px; margin-top: -300px; position: fixed; background-color: #f00; z-index: 6; } .thumbnail { width: 50px; height: 50px; } html: <img class="thumbnail" src="http://4.bp.blogspot.com/-uhbdp2esxng/txneptvi92i/aaaaaaaaaky/upfqis7zto0/s1600/rihanna-wallpaper.jpg"> jquery: $(document).ready(function() { $('.thumbnail').on('click', function() { var img = $('<img />',{src:this.src,'class':'full'}); $('.full').html(img).show(); console.log('done!'); }); }); try looking how jquery works. $(document).ready(function() { $('.thumbnail').on('click', function(...
Read more