PHP Query causes SQL Server Tables to disappear and reappear - php

Question

We have a website that accesses a SQL Server 2005 server for one query. Currently, the site is in ASP, we are moving it to PHP, and the PHP one is currently being tested. After we run a few successful queries on the PHP site, it returns the "Error in database query. Please try again later" line in the code below. When I rewrote that line with sqlsrv_errors to elaborate, it told me that the table didn't exist. There are about 40 tables in the database, but after the error happens it only shows 8 of them in Management Studio. However, if I allow it to sit for about 5 minutes, all of the tables are restored. No matter how many times the old ASP site is used, the table does not do this. However, when the tables disappear from using the new site, the old site shows inaccessible for a few minutes until the tables re-appear in SQL Server management studio. I didn't see any kind of connection limits on the SQL Server, so I don't know whether it's something I'm doing in the PHP SQL queries or within the SQL Server properties.
<?php
include ("dbvals.inc.php");
if (!empty($_POST['lastnamebox'])) {
$dbhandle = sqlsrv_connect($dbServer, $connectioninfo);
if($dbhandle == false){
echo "Error connecting to database. Please try again later. ";
}
else{
$query = "SELECT * FROM Person WHERE LastName LIKE '%' + ? +
'%' AND InactiveFlag = 'N' ORDER BY LastName, FirstName";
$params = array();
array_push ($params, $_POST['lastnamebox']);
$results = sqlsrv_query($dbhandle, $query, $params);
if($results == false){
echo "Error in database query. Please try again later.";
//This is printed when database tables temporarily disappear
}
else
{
$row = sqlsrv_fetch_array( $results, SQLSRV_FETCH_ASSOC);
if($row){
do{
echo "<tr><td class='tablecell'>";
echo $row['LastName'] . "," . $row['FirstName'] . "<br>";
echo "Address: " . $row['Address'] . "<br>";
echo "City, State, Zip: " . $row['CSZ'] . "<br>";
echo "</tr></td'>";
}while($row = sqlsrv_fetch_array( $results, SQLSRV_FETCH_ASSOC));
}
else{
echo "No results found. Please try another query.";
}
}
}
sqlsrv_free_stmt($results);
sqlsrv_close($dbhandle);
}
else {
echo "Please type a value in the search box.";
}
?>

Answer 1

The $query is wrong to begin with. Change it to:
$query = "SELECT * FROM Person WHERE LastName LIKE '%' + ? +
'%' AND InactiveFlag = 'N' ORDER BY LastName, FirstName";
Not sure about the tables disappearing though. What driver are you using?

Answer 2

Just another issue I'm seeing with the code not sure if it's related to your problem. or another copy error but here it is.
if ($r1 = sqlsrv_fetch_array($results)) {
while( $row = sqlsrv_fetch_array( $results, SQLSRV_FETCH_ASSOC)){
The first fetch should also have '($results,, SQLSRV_FETCH_ASSOC)'
Additional that check is going to eat the first returned record which may or may NOT be what you intended.
Also it is possibly that PHP seeing some results in the while as false even though they aren't and the server is still waiting on you to finish getting the rest. Seen code like that cause 'Server has got away' errors in MySQL which could be what is going on here as well.
Not sure of the syntax but a sqlsrv_clode_cursor() just before the connection close might also fix your issue if there's some kind of connection polling going on. Could be simply running out of connection or getting old one in a incorrect state.

Answer 3

SELECT * FROM Person WHERE AND LastName LIKE
Looks like there something missing between the WHERE and AND to me.
I don't know SQL Server really so it could allow that but it's not standard SQL. Depending on how it's reacting to that error I could see it 'Going away' so to say and reporting tables missing.