mysqli - sometimes my sql connection keep saying "PHP Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result" -

mysqli - sometimes my sql connection keep saying "PHP Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result" -

actually, connected 3 databases in different server, got problem in mysqli_query.

sometimes worked fluently without error, showed "php warning: mysqli_fetch_array() expects parameter 1 mysqli_result".. don't know happen, ocurred sometimes.

here connection : connection.php

<?php $databasename1 = "db_name1"; $dbhostname1 = "host1"; $dbusername1 = "username"; $dbpassword1 = "password"; $databasename2q = "db_name2"; $dbhostname2 = "host2"; $dbusername2 = "username2"; $dbpassword2 = "password2"; $databasename3q = "db_name3"; $dbhostname3 = "host3"; $dbusername3 = "username3"; $dbpassword3 = "password3"; $mysqli1 = mysqli_connect("$dbhostname1", "$dbusername1", "$dbpassword1", "$databasename1"); $mysqli2 = mysqli_connect("$dbhostname2", "$dbusername2", "$dbpassword2", "$databasename2q"); $mysqli3 = mysqli_connect("$dbhostname3", "$dbusername3", "$dbpassword3", "$databasename3q"); $server[1] = $mysqli1; $server[2] = $mysqli2; $server[3] = $mysqli3; $count_db = 3; if(!$mysqli1){ echo "error connect server 1st"; die(); } if(!$mysqli2){ echo "error connect server 2nd"; die(); } if(!$mysqli3){ echo "error connect server 3rd"; die(); } if (mysqli_connect_errno()) { printf("connect failed: %s\n", mysqli_connect_error()); exit(); } ?>

task1.php

<?php include("connection.php") for($i=1;$i<=$count_db;$i++){ $conn = $server[$i]; $array = mysqli_fetch_array(mysqli_query($conn,"select * `table`")); $task = $array["field"]; } ?>

anyone guys can help?

do

for($i=1;$i<=$count_db;$i++){ $conn = $server[$i]; $resultset = mysqli_query($conn,"select * `table`") if(!$resultset){ //do continue; //if don't want break } $array = mysqli_fetch_array($resultset); $task = $array["field"]; }

php mysqli