我正在使用下面的代码来构建一个Google图表,以便在一年内对应于一周数字的MySQL表格中提取所有条目。目前,周数开始于星期天,我想改变这一点,以便他们在星期一开始,但我不知道如何做到这一点。如何在PHP/MySQL中使用Week(Date)时将星期几的第一天设置为星期一?
$i=1;
while($i<=53)
{
$week_start = new DateTime();
$week_start->setISODate(2013,$i+1);
$date_display = $week_start->format('j M Y');
$sessions = $wpdb->get_var($wpdb->prepare("SELECT Sum(Due) from patient_sessions WHERE Type='Session' AND Week(Date)='$i'"));
$temp = array();
$temp[] = array('v' => (string) $date_display);
$temp[] = array('v' => (string) $sessions);
$rows[] = array('c' => $temp);
$i++;
}
修改后的代码
$sessions = $wpdb->get_results($wpdb->prepare("SELECT Due,Date from patient_sessions WHERE Type='Session'"));
$work_times = $wpdb->get_results($wpdb->prepare("SELECT Amount,Date from work_times"));
$expenses = $wpdb->get_results($wpdb->prepare("SELECT Amount,Date from expenses WHERE Client='Psychotherapy'"));
$i=1;
while($i<=53) {
$week_start = new DateTime();
$week_start->setISODate(2013,$i+1);
$date_display = $week_start->format('j M Y');
$session_total = 0;
$work_time_total = 0;
$expense_total = 0;
foreach ($sessions as $session) {
if (date("W", strtotime($session->Date)) == $i) {
$session_total = ($session_total+$session->Due);
}
}
foreach ($work_times as $work_time) {
if (date("W", strtotime($work_time->Date)) == $i) {
$work_time_total = ($work_time_total+$work_time->Amount);
}
}
foreach ($expenses as $expense) {
if (date("W", strtotime($expense->Date)) == $i) {
$expense_total = ($expense_total+$expense->Amount);
}
}
$balance = ($session_total + $work_time_total - $expense_total);
$temp = array();
$temp[] = array('v' => (string) $date_display);
$temp[] = array('v' => (string) $balance);
$rows[] = array('c' => $temp);
$i++;
}
这似乎是一个非常低效的做法!只需一次获取所有结果,然后遍历结果集。 – Strawberry 2013-04-24 16:11:49
@Strawberry你可能是对的。你的意思是使用'来自patient_sessions的SELECT *',然后使用循环遍历所有结果?我注意到图表加载速度很慢。据推测这是为什么?一般情况下,PHP循环的运行速度比以上述方式使用查询快吗? – Nick 2013-04-24 17:06:02
通常(当然也有例外),您希望尽可能少地往返数据库。你的策略使53次旅行。我做了1.但是,问题不在于“SELECT *”。这是“WHERE Week(Date)='$ i'”。请参阅GROUP BY。 – Strawberry 2013-04-25 08:35:51