基于行值

Question

我有一个包含两种不同GPS设备类型的数据库。我需要创建一个基于GPS设备类型进行过滤的查询。

（gl200）设备类型查询如下所示：

SELECT t1.deviceid, t1.devicetime, t1.latitude, t1.longitude
FROM positions t1
INNER JOIN
    (SELECT MAX(id) as LatestGpsPoint
    FROM positions
        WHERE deviceid IN
            (SELECT deviceid FROM device_group WHERE groupid = 7)
            AND valid = 1
            AND attributes LIKE '%FRI%'
            AND network != 'null'
            AND devicetime >= (SELECT deploymentdate 
                              FROM devices
                              WHERE id = deviceid
                              LIMIT 1
            )
            GROUP BY deviceid
    ) t2
ON t1.id = t2.LatestGpsPoint
ORDER BY t1.deviceid ASC
LIMIT 0,100

其他设备类型（dmt）查询如下所示：

SELECT t1.deviceid, t1.devicetime, t1.latitude, t1.longitude
FROM positions t1
INNER JOIN
    (SELECT MAX(id) as LatestGpsPoint
    FROM positions
        WHERE deviceid IN
            (SELECT deviceid FROM device_group WHERE groupid = 7)
            AND valid = 1
            AND devicetime >= (SELECT deploymentdate 
                              FROM devices
                              WHERE id = deviceid
                              LIMIT 1
            )
            GROUP BY deviceid
    ) t2
ON t1.id = t2.LatestGpsPoint
ORDER BY t1.deviceid ASC
LIMIT 0,100

我正在尝试在其中放置IF ELSE END语句，以根据t1.protocol ='gl200'或'dmt'更改搜索条件。

Answer 1

尝试UNION：

(SELECT t1.deviceid, t1.devicetime, t1.latitude, t1.longitude
FROM positions t1
INNER JOIN
    (SELECT MAX(id) as LatestGpsPoint
    FROM positions
        WHERE deviceid IN
            (SELECT deviceid FROM device_group WHERE groupid = 7)
            AND valid = 1
            AND attributes LIKE '%FRI%'
            AND network != 'null'
            AND devicetime >= (SELECT deploymentdate 
                              FROM devices
                              WHERE id = deviceid
                              LIMIT 1
            )
            GROUP BY deviceid
    ) t2
ON t1.id = t2.LatestGpsPoint)
UNION
(SELECT t1.deviceid, t1.devicetime, t1.latitude, t1.longitude
FROM positions t1
INNER JOIN
    (SELECT MAX(id) as LatestGpsPoint
    FROM positions
        WHERE deviceid IN
            (SELECT deviceid FROM device_group WHERE groupid = 7)
            AND valid = 1
            AND devicetime >= (SELECT deploymentdate 
                              FROM devices
                              WHERE id = deviceid
                              LIMIT 1
            )
            GROUP BY deviceid
    ) t2
ON t1.id = t2.LatestGpsPoint)

Answer 2

if语句是可能的，但我认为你可以用case语句来做。代码的唯一区别是这部分：

SELECT t1.deviceid, t1.devicetime, t1.latitude, t1.longitude
FROM positions t1
INNER JOIN
    (SELECT MAX(id) as LatestGpsPoint
    FROM positions
        WHERE deviceid IN
            (SELECT deviceid FROM device_group WHERE groupid = 7)
            AND valid = 1
            AND CASE WHEN deviceID = 'gl200' --however you id the device
                      THEN attributes LIKE '%FRI%' --gl200
                      ELSE 1=1  --dmt
                END

            AND CASE WHEN deviceID = 'gl200' --however you id the device
                      THEN network != 'null' --gl200
                      ELSE 1=1 --dmt
                END
            AND devicetime >= (SELECT deploymentdate 
                              FROM devices
                              WHERE id = deviceid
                              LIMIT 1
            )
            GROUP BY deviceid
    ) t2
ON t1.id = t2.LatestGpsPoint
ORDER BY t1.deviceid ASC
LIMIT 0,100

仅适用于第一个查询，即GL200设备。

案例陈述将在angular.module('ecommerce').factory('CartService', ['$webSql', '$http', '$q', 'urls', function ($webSql, $http, $q, urls) { var addToCart = function () {//body of function} var factory = { addToCart: addToCart, removeCart: removeCart }; return factory;] } ]); 之后开始。

angular.module('ecommerce').factory('CartService',
['$webSql', '$http', '$q', 'urls',
    function ($webSql, $http, $q, urls) {
        function addTocart () {//Body of function}
        var factory = {
            addToCart: addToCart,
            removeCart: removeCart
        };

        return factory;]
    }
]);