php - MYSQL gives same response '0 rows affected' in different situations -


mysql update query give same response in different situations

"0 rows affected. (query took 0.0789 sec)"

1) clause not matched

2) clause matched given value same existing value

ex:
assume user_id = '86' not exist in table

update `undergraduate` set `faculty` = 'efac' `user_id` = '86'

assume user_id = '86' exist. value 'efac' in there 

update `undergraduate` set `faculty` = 'efac' `user_id` = '86'

question better way identify both conditions ?

i'm using : mysql : 

+-------------------------+ | @@version               | +-------------------------+ | 5.6.19-0ubuntu0.14.04.1 | +-------------------------+

php : 5.5.9-1 (pdo)

mysql command line

if using mysql command line tool output given let differentiate 2 scenarios.

if entry doesn't exist:

+---------------+---------+ | user_id       | faculty | +---------------+---------+ | 80            | abc     | +---------------+---------+  mysql> update `undergraduate` set `faculty` = 'efac' `user_id` = '86'; query ok, 0 rows affected (0.00 sec) rows matched: 0  changed: 0  warnings: 0

if entry exist, isn't updated:

+---------------+---------+ | user_id       | faculty | +---------------+---------+ | 80            | abc     | | 86            | efac    | +---------------+---------+  mysql> update `undergraduate` set `faculty` = 'efac' `user_id` = '86'; query ok, 0 rows affected (0.00 sec) rows matched: 1  changed: 0  warnings: 0

if entry exist, , updated:

+---------------+---------+ | user_id       | faculty | +---------------+---------+ | 80            | abc     | | 86            | bcd     | +---------------+---------+  mysql> update `undergraduate` set `faculty` = 'efac' `user_id` = '86'; query ok, 0 rows affected (0.00 sec) rows matched: 1  changed: 1  warnings: 0

php - pdo

pdo unfortunately doesn't provide mechanism both rows matched and rows changed query, can choose 1 want. default return number of rows changed, option can specified on connection return number of rows match instead:

$db = new pdo('mysql:dbname=database;host=host', 'username', 'password', array(     pdo::mysql_attr_found_rows => true ));

php - mysqli

the mysqli functions can same pdo in terms of choosing between matched , updated:

$db = mysqli_init(); $db->real_connect('host', 'username', 'password', 'database', '3306', null, mysqli_client_found_rows);

but can call function mysqli_info() / $db->info() (see http://php.net/manual/en/mysqli.info.php) , return string matched / updated rows parse:

records: 3 duplicates: 0 warnings: 0

Comments

Post a Comment

Popular posts from this blog

javascript - Google App Script ContentService downloadAsFile not working -

i have web app developed using google app script htmlservice , html form, populating excel sheet in google drive using spreadsheetapp . , 1 section calling contentservice download data excel file. function doget(e) { // read excel sheet //getappfile(); // render application html template return htmlservice.createtemplatefromfile('index').evaluate() .settitle('go smart') .setsandboxmode(htmlservice.sandboxmode.iframe); } function downloaddoublequatecsvfile() { var sheetid = propertiesservice.getscriptproperties().getproperty('sheetid'); var ss = spreadsheetapp.openbyid(sheetid).getactivesheet(); //var ss = spreadsheetapp.getactivespreadsheet().getactivesheet(); var maxcolumn = ss.getlastcolumn(); var maxrow = ss.getlastrow(); var data = ss.getrange(1, 1, maxrow, maxcolumn).getvalues(); if (data.length > 1) { var csv = ""; (var row = 0; row < data.length; row++) { (var c...
Read more

javascript - Function overwritting -

is there way overwrite function or event handling in function? using addeventlistener, can have many event handlers on element want var test=document.getelementbyid("div"); test.addeventlistener("click",function(){alert("im first");},false); test.addeventlistener("click",function(){alert("im second");},false); // alerts "im first" , after "im second" but if want overwrite function/event example based on client width example this function one() { alert("first"); } function two() { alert("second"); } window.onresize = function() { var test = document.getelementbyid("div"); if (window.innerwidth > 500) { test.onclick = 1 } else { test.onclick = two; } } is possible in javascript? in case use effective little known approach. addeventlistener can accept object property handleevent event handler. in case it's easy overwr...
Read more

php - Find a regex to take part of Email -

i have following emails need extract part from: bestellnummer xxx: 1 von xxx, 1er pack ------------- anfang der nachricht ------------- foo bar baz foo bar baz // <<<<< need text here ------------- ende der nachricht ------------- ------------- anfang der nachricht ------------- foo bar baz foo bar baz ------------- ende der nachricht ------------- there 0 unlimited occurences of ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- and i'm able extract first part regex: $re = "/------------- .*? -------------.?(.*?).?------------- .*? -------------/s"; but, i'm quite new on learning regex, i'm pretty sure there must better regex extract part (foo bar baz foo bar baz) of text between ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- as can in different languages, i'm using .? to match between hyphens. i...
Read more