進行僅顯示沒有空值的行的查詢

Question

我正在嘗試創建一個查詢語句，該語句將僅捕獲其列中不包含空值的行。 但是我不確定該怎么做。

這是查詢語句：

    $query = "SELECT scrap_wafers.lot, scrap_wafers.wafer_cell, scrap_wafers.flow, ".
"scrap_wafers.route, scrap_wafers.scrap_date, scrap_wafers.scrap_comment, ".
"scrap_type_names.scrap_tag_name, scrap_wafers.engineer, scrap_wafers.disposition_date, ".
"scrap_wafers.disposition_comment, scrap_wafers.location, scrap_wafers.serial_sw, scrap_wafers.operator ".
"FROM scrap_wafers ".
"LEFT JOIN scrap_type_names ON scrap_type_names.serial_stn = scrap_wafers.serial_stn ".
"$cstring ".
"GROUP BY scrap_wafers.serial_sw ".
"ORDER BY scrap_wafers.scrap_date DESC ".
"LIMIT $numrecs";

$ criteria包含：

$criteria = array();
if (!empty($lot)) {
 $lotarray = explode(',', $lot);
 $lot_criteria_str = "(";
 foreach ($lotarray as $lottmp) {
  $lot_criteria_str = $lot_criteria_str . "scrap_wafers.lot like '%$lottmp%' OR ";
 } 
 $lot_criteria_str = substr($lot_criteria_str,0,-3); 
 $lot_criteria_str = $lot_criteria_str . ")";
 $criteria[] = $lot_criteria_str;
 }
if (!empty($wafer_cell)) {
 $waferarray = explode(',', $wafer_cell);
 $wafer_criteria_str = "(";
 foreach ($waferarray as $wafertmp) {
  $wafer_criteria_str = $wafer_criteria_str . "scrap_wafers.wafer_cell like '%$wafertmp%' OR ";
 } 
 $wafer_criteria_str = substr($wafer_criteria_str,0,-3); 
 $wafer_criteria_str = $wafer_criteria_str . ")";
 $criteria[] = $wafer_criteria_str;
 } 
    if (!empty($serial_flow)) $criteria[] = "scrap_wafers.serial_flow = '$serial_flow'";
    if (!empty($serial_route)) $criteria[] = "scrap_wafers.serial_route = '$serial_route'"; 
    if (!empty($operator)) $criteria[] = "scrap_wafers.operator = '$operator'";     
    if (!empty($serial_stn)) $criteria[] = "scrap_wafers.serial_stn = '$scrap_tag_name'";               
    if (!empty($scrap_date)) $criteria[] = "scrap_wafers.scrap_date = '$scrap_date'";   
    if (!empty($serial_step)) $criteria[] = "scrap_wafers.serial_step = '$serial_step'";    
    if (!empty($location)) $criteria[] = "scrap_wafers.location = '$location'";             
    if (!empty($completeness)) {
        if ($completeness == 'Default') { 
        // Do nothing
        }
        else if ($completeness == 'Incomplete') {
            $criteria[] = "scrap_wafers.disposition_date = null AND scrap_wafers.engineer = null AND ".
            "scrap_wafers.disposition_comment = null AND scrap_wafers.location = null AND  ".
            "scrap_wafers.serial_stn = null";
        }
        else if ($completeness == 'Complete') {
            $criteria[] = "scrap_wafers.disposition_date = not null AND scrap_wafers.engineer = not null AND ".
            "scrap_wafers.disposition_comment = not null AND scrap_wafers.location = not null AND  ".
            "scrap_wafers.serial_stn = not null";
        }
    }   
$cstring = "";
    if (count($criteria) > 0) {
        $cstring = "WHERE ".join(" AND ", $criteria);
    } else {
        $cstring = "WHERE 1=1 ";
    }

$ completeness是我嘗試過濾空值（不完整）或沒有空值（完整）的地方。

Answer 1

您需要使用IS NULL ，而不是= null 。

...

else if ($completeness == 'Incomplete') {
    $criteria[] = "scrap_wafers.disposition_date IS NULL AND scrap_wafers.engineer IS NULL AND ".
    "scrap_wafers.disposition_comment IS NULL AND scrap_wafers.location IS NULL AND  ".
    "scrap_wafers.serial_stn IS NULL";
}
else if ($completeness == 'Complete') {
    $criteria[] = "scrap_wafers.disposition_date IS NOT NULL AND scrap_wafers.engineer IS NOT NULL AND ".
    "scrap_wafers.disposition_comment IS NOT NULL AND scrap_wafers.location IS NOT NULL AND  ".
    "scrap_wafers.serial_stn IS NOT NULL";
}

...