以下代码段有什么问题？

The PHP code is as follows:

if($duration!='' && $duration_in_hrs!='') {
    $duration_in_sec = $duration_in_hrs * 60 * 60;
    //echo $grid->mSqlArr['where']; die;
    if(empty($grid->mSqlArr['where']) && $grid->mSqlArr['where']=='')
        $grid->mSqlArr['where'] = " tests.test_duration = "."'"$duration"'"." ".$duration_in_sec;
    else 
        $grid->mSqlArr['where']  .= " AND tests.test_duration "."'"$duration"'"." ".$duration_in_sec;
}

If I comment the code from line no. 4 to 7 and echo the value of variable $grid->mSqlArr['where'] it's printing the output is_test_cancled='0' AND is_test_archive='0' But when I remove the comments and run the code the blank screen appears, I can't get how this is happening. I tried to debug, during that I got the following error PHP Parse error: syntax error, unexpected T_VARIABLE in view_tests.php on line 218 Errors parsing view_tests.php

Can you help me in resolving this error. I didn't get after having value how the variable can be unrecognized? Thanks in advance.

The syntax highlighting is a dead giveaway. Check the following line (and the one two below it in your original code snippet):

$grid->mSqlArr['where'] = " tests.test_duration = "."'"$duration"'"." ".$duration_in_sec;

You have a string - " tests.test_duration = "."'" and then after it you have a variable $duration and then another string "'"." ".$duration_in_sec.

If you're meaning to concatenate them all together into one string, you should add the $duration into the string, eg.

$grid->mSqlArr['where'] = " tests.test_duration = "."'".$duration."'"." ".$duration_in_sec;

(note the extra .s around the $duration variable)

You are building your strings wrong

$grid->mSqlArr['where'] = " tests.test_duration = "."'"$duration"'"." ".$duration_in_sec;

should probably be

$grid->mSqlArr['where'] = " tests.test_duration = '$duration' "  . $duration_in_sec;

although I don't know what it is that you're trying to build exactly. But you need a . between each string that you are concatenating together. Also note that you can embed variables in double-quoted strings and they will expand out.