[Resolved] [Resolved] How Do We Check Double Inserted Data In A Db?

Blaze___

Hi Guys !!!
I am looking for some help here.
I have made a database with my sql and I want php whenever I add new data to this database and has been already add to inform me when i fill the fields of the inserted item.
Thanks for your time

drew010

if you want to see if data has already been inserted, you will have to use a select statement to check the data and see if it returns any rows prior to inserting data. if its already there, you tell the user they have to enter new data, otherwise you can insert it.

euph

If you try to add a record with a primary key that already exists the insert will return an error stating that the key already exists. You can trap this and return the error back to the user saying that the record already exists.

so you could execute the mysql statement, if it fails then check mysql_errno() to see if it has returned a key already exists error, and display a bit of text on the page stating so.

leatherback

Hi Euph,

Generally speraking, you do not insert a primary key, but have it auto-increment upon insertion of the record. So checking for a primary key is useless, unless it is an update statement, when you already know the ID exists. Or am I missing the point here?

I'd go with drew. Check for certain values, by running a query. (Say: Username & password & common name & date of birth all match the newly registered person, then that person alreday exists)
If you get a result (mysql_num_rows($result) > 0 ) then the record exists.

euph

A primary key doesn't have to be an auto-inc num but a unique value....

Obviously if it is then yes an additional query is required to check beforehand (drews post), if not it is possible to check and update in one hit.

Blaze___

Thanks for your help but because I have never used php code before if it is not trouble for you could you please write me an example for the quote in php code?
Thanks again for your help.

videxx

hye there.. i'm sure u are in a blur stage in solving ur problem there.. i can give a sample of mine, where i can check the existed record in a database by inserting a few line of codes..

//at first u need to connect ur sql to the database
//i used a pre-define variable to connect my database
//hope u could modify it to where it is suitable
$conn = phpmkr_db_connect(HOST, USER, PASS,DB);

//i have a few actions with some conditions- but i only show the display record
switch ($sAction)
{
//this is the code to check an ecisting record in database
	case "I": // Get a record to display
		if (LoadData($sKey,$conn)) { // Load Record based on key
//this is the msg that will prompt out if it existed
			$HTTP_SESSION_VARS["ewmsg"] = "Existed Record for Key = " . $sKey;
			phpmkr_db_close($conn);
			header("Location: CustomerList.php");
			exit();
		}
//this code is to check whether the record has not yet been added
		if (!LoadCusData($sKey,$conn)) { // Load Record based on key
			$HTTP_SESSION_VARS["ewmsg"] = "No Record Found for Key = " . $sKey;
			phpmkr_db_close($conn);
			header("Location: CustomerList.php");
			exit();
		}
		break;
}

then i have the function which is called LoadData to check whether the record is existed..

//-------------------------------------------------------------------------------
// Function LoadData
// - I Load the Data based on a Key selected at a page before the display page (Value sKey is passed to this page)
// - Variables setup: field variables

function LoadData($sKey,$conn)
{
	global $HTTP_SESSION_VARS;
	$sKeyWrk = "" . addslashes($sKey) . "";
$sSql = "SELECT bla bla bla 
              FROM table";
	$sWhere .= "(CustomerID = " . $sKeyWrk . ")";
	$sGroupBy = "";
	$sHaving = "";
	$sOrderBy = "";
	$sSql .= " WHERE " . $sWhere;
	if ($sGroupBy <> "") {
		$sSql .= " GROUP BY " . $sGroupBy;
	}
	if ($sHaving <> "") {
		$sSql .= " HAVING " . $sHaving;
	}
	if ($sOrderBy <> "") {
		$sSql .= " ORDER BY " . $sOrderBy;
	}
	$rs = phpmkr_query($sSql,$conn) or die("Failed to execute query: " . phpmkr_error() . '<br>SQL: ' . $sSql);
	if (phpmkr_num_rows($rs) == 0) {
		$LoadData = false;
	}else{
		$LoadData = true;
		$row = phpmkr_fetch_array($rs);

	// Get the field contents
                            // U must retrieve fields for the record
                            // these are my examples - to help u
	$GLOBALS["x_CustomerID"] = $row["CustomerID"];
	$GLOBALS["x_JobName"] = $row["JobName"];
	$GLOBALS["x_AgencyName"] = $row["AgencyName"];
	$GLOBALS["x_JobName"] = $row["JobName"];
	$GLOBALS["x_TrainingName"] = $row["TrainingName"];
}
phpmkr_free_result($rs);
return $LoadData;
}

this is how i do my checking.. BUT, correct me if i'm wrong.. 😃
my situation is: i have a page to list all of the records.. each of it has a link to add records' details and edit the record.. for a record which is existed, when the user click add records' details, a msg will prompt out telling the record is exist in database.. and if u noticed, i have another condition to check whether the record is existed or not.. say the user click edit to a non-existed record, a msg will prompt out saying the record is not existed yet..

another things that u need to know about my coding.. my codes are actually comprises of 5 tables which links up together.. that is why my database checking is a bit fuzzy.. u might be confused.. did u?

emm.. for sure i didnt paste the full complete codes here.. but if u are interested to see the real example, and wanted to understand better, you can request it and ask from me later..

hope i dont confused u.. and i also hope that this code can help u..

Regards, videxx 🆒

Blaze___

Thanks a lot. You have been very helpful to me.Thanks again.

videxx

is ur problem solved? i wonder, did my brief explainations before had helped u? btw, i do hope that u can change this thread status to RESOLVED..

anyway, you are most welcome... if u need anytin, do tell me and i'll help the best i can..

have a gud day Blaze(!)~

Regards, videxx 😃