Question

我在MySQL数据库中有一个booking表，我需要获取3个数据。

1）总预订
2）待定预订（is_confirm = 1）
3）完成预订（is_confirm = 0）

现在，我正在编写3个单独的查询来获取此信息但是如何使用1个查询来获取它？

当前查询：

$booking = new Admin;
$booking->rowQuery("SELECT count(bid) AS totalBooking FROM booking");
$bookingData = $booking->result->fetch_assoc();
$totalBooking = $bookingData['totalBooking'];

$booking->rowQuery("SELECT bid FROM booking WHERE is_confirm = 1 ");
$completeBooking = $booking->rows;

$booking->rowQuery("SELECT bid FROM booking WHERE is_confirm = 0 ");
$pendingBooking = $booking->rows;

Answer 1

SELECT count(bid) AS totalBooking FROM booking
UNION
SELECT bid FROM booking
WHERE is_confirm=1
UNION
SELECT bid FROM booking
WHERE is_confirm=0

Answer 2

你可以使用case sql。试试这个：

SELECT
    COUNT(CASE WHEN is_confirm = 1 THEN 1 END) AS confirmCount,
    COUNT(CASE WHEN is_confirm = 0 THEN 1 END) AS noconfirmCount,
    COUNT(*) AS total
FROM booking;

Answer 3

聚合函数通常会跳过null，包括group_concat。如果您以后不介意explode结果字符串，可以使用case表达式来获取ID的总预订和逗号分隔字符串：

SELECT COUNT(bid) AS totalBooking,
       GROUP_CONCAT(CASE is_confirm WHEN 1 THEN bid END) AS pendingBookings,
       GROUP_CONCAT(CASE is_confirm WHEN 0 THEN bid END) AS completeBookings
FROM   booking

如何最小化sql查询

3 个答案: