分表分頁問題

( 此文章只做自己工作記錄使用）

假如每天一個表表的名稱定義格式爲：sys_client_20200106

1、確定要分頁的數據總表數(table_count)

 sys_get_timespan（爲把日期差換算爲天數的函數）

$day_count=sys_get_timespan($start_date,$end_date,'d');
$day_count=$day_count+1;

2、循環查出沒個表滿足條件的數量、limit的起始位置(table_index)和結束位置(table_end)並統計所有滿足條件的數據數量total_count

            $total_count=0;
            for ($i=0;$i<$day_count;$i++)
            {
                $temp_date=date("Ymd",strtotime('-'.$i.' day',strtotime($end_date)));
                $table_name="sys_client_".$temp_date;

                $sql_suffix=" from $table_name where 1=1 ";
                if ($regdate_start) $sql_suffix .= "and regdate>='$regdate_start' ";
                if ($regdate_end) $sql_suffix .= "and regdate<='$regdate_end' ";
            

                $sqlstr="select count(id) $sql_suffix";
                //echo $sqlstr."<br>";
                $table_count=$this->get_one_bysql($sqlstr);
                if ($table_count>0)
                {
                    $total_count+=$table_count;
                    $table_sub_arr[$table_sub_j]['name']=$table_name;
                    $table_sub_arr[$table_sub_j]['count']=$table_count;
                    if ($table_sub_j==0) {
                        $table_sub_arr[$table_sub_j]['start_index']=0;
                        $table_sub_arr[$table_sub_j]['end_index']=$table_count-1;
                    }
                    else
                    {
                       
                        $table_sub_arr[$table_sub_j]['start_index']=$total_count - $table_count;
                        $table_sub_arr[$table_sub_j]['end_index']=$total_count-1;
                    }
                    $table_sub_j++;
                }
            }

 

3、確定請求分頁數據請求需要查詢的表的開始位置和需要查詢的limit數據條數確定查詢每個表的sql語句，用union連接組合每個查詢語句即可

 $query_table_arr=[];
            $j=0;
            for ($i=0;$i<count($table_sub_arr);$i++)
            {
                if ($start>=$table_sub_arr[$i]['start_index'] && $end<=$table_sub_arr[$i]['end_index'])
                {
                    $query_table_arr[$j]['name']=$table_sub_arr[$i]['name'];

                    $query_table_arr[$j]['start_index']=$start-$table_sub_arr[$i]['start_index'];
                    $query_table_arr[$j]['limitcount']=$page_count;

                    break;
                }

                if ($start>=$table_sub_arr[$i]['start_index'] && $end>=$table_sub_arr[$i]['end_index'])
                {
                    $query_table_arr[$j]['name'] = $table_sub_arr[$i]['name'];
                    $query_table_arr[$j]['start_index'] = $start - $table_sub_arr[$i]['start_index'];
                    $query_table_arr[$j]['limitcount'] = $page_count;
                    $j++;
                    continue;
                }

                if ($start<$table_sub_arr[$i]['start_index'] && $end>$table_sub_arr[$i]['end_index'])
                {
                    $query_table_arr[$j]['name'] = $table_sub_arr[$i]['name'];
                    $query_table_arr[$j]['start_index'] = 0;
                    $query_table_arr[$j]['limitcount'] = $page_count;
                    $j++;
                    continue;
                }

                if ($start<$table_sub_arr[$i]['start_index'] && $end<$table_sub_arr[$i]['end_index'] && $end>$table_sub_arr[$i]['start_index'])
                {
                    $query_table_arr[$j]['name'] = $table_sub_arr[$i]['name'];
                    $query_table_arr[$j]['start_index'] = 0;
                    $query_table_arr[$j]['limitcount'] = $end - $table_sub_arr[$i]['start_index'] + 1;

                    $j++;
                    continue;
                }
            }
            //dump($query_table_arr);
            $source_sqlstr = "";
            for ($i=0;$i<count($query_table_arr);$i++)
            {
                $table_name=$query_table_arr[$i]['name'];

                if ($table_name) {
                    $sql_suffix=" from $table_name where 1=1 ";
                    if ($regdate_start) $sql_suffix .= "and regdate>='$regdate_start' ";
                    if ($regdate_end) $sql_suffix .= "and regdate<='$regdate_end' ";
                    

                    $start=$query_table_arr[$i]['start_index'];

                    $source_sqlstr .= "(";
                    if (!$export)
                        $source_sqlstr .= "select * $sql_suffix order by regdate desc limit $start,".$query_table_arr[$i]['limitcount'];
                    else $source_sqlstr .= "select * $sql_suffix order by regdate desc";

                    $source_sqlstr .= ") UNION";
                }

            }

            $source_sqlstr=substr($source_sqlstr,0,-5);

打印：dump($query_table_arr); 

array(2) {
  [0] => array(3) {
    ["name"] => string(19) "sys_client_20200206"
    ["start_index"] => int(1090)
    ["limitcount"] => int(10)
  }
  [1] => array(3) {
    ["name"] => string(19) "sys_client_20200205"
    ["start_index"] => int(717)
    ["limitcount"] => int(10)
  }
}

打印$source_sqlstr如下： 

(select * from sys_client_20200206 where 1=1 and regdate>='2020-01-04 00:00:00' and regdate<='2020-02-06 15:23:53' and controller_id=21 order by regdate desc limit 1090,10) UNION(select * from sys_client_20200205 where 1=1 and regdate>='2020-01-04 00:00:00' and regdate<='2020-02-06 15:23:53' and controller_id=21 order by regdate desc limit 717,10)