我想要的:
- 用户输入邮政编码或城市名称
- 我在数据库中搜索5个最接近的位置
- 向用户显示该位置附近的5个最近位置
到目前为止我所拥有的:
假设有一个包含以下内容的地点表:
(大约有16000行)
CREATE TABLE `locations` (
`locationID` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(150) NOT NULL,
`firstname` varchar(100) DEFAULT NULL,
`lastname` varchar(100) DEFAULT NULL,
`street` varchar(100) NOT NULL,
`city` varchar(100) NOT NULL,
`state` varchar(100) NOT NULL,
`zipcode` varchar(10) NOT NULL,
`phone` varchar(20) NOT NULL,
`web` varchar(255) DEFAULT NULL,
`machine` enum('Unbekannt','Foo','Bar') DEFAULT 'Unbekannt',
`surface` enum('Unbekannt','Foo','Bar','') DEFAULT 'Unbekannt',
PRIMARY KEY (`locationID`)
) ENGINE=InnoDB AUTO_INCREMENT=25 DEFAULT CHARSET=utf8
- ID(编号)
- name(名称)
- zip code(邮政编码)
- city(城市)
现在我有了第二个包含全球所有城镇的表格:
(大约340万行)
CREATE TABLE `geoData` (
`geoID` int(11) NOT NULL AUTO_INCREMENT,
`countryCode` char(2) NOT NULL,
`zipCode` varchar(20) NOT NULL,
`name` varchar(180) NOT NULL,
`state` varchar(100) NOT NULL,
`stateCode` varchar(20) NOT NULL,
`county` varchar(100) NOT NULL,
`countyCode` varchar(20) NOT NULL,
`community` varchar(100) NOT NULL,
`communityCode` varchar(20) NOT NULL,
`lat` mediumint(6) NOT NULL,
`lon` mediumint(6) NOT NULL,
PRIMARY KEY (`lon`,`lat`,`geoID`) USING BTREE,
KEY `geoID` (`geoID`)
) ENGINE=InnoDB AUTO_INCREMENT=16482 DEFAULT CHARSET=utf8
/*!50100 PARTITION BY RANGE (lat)
(PARTITION p0 VALUES LESS THAN (-880000) ENGINE = InnoDB,
PARTITION p1 VALUES LESS THAN (-860000) ENGINE = InnoDB,
PARTITION p2 VALUES LESS THAN (-840000) ENGINE = InnoDB,
PARTITION p3 VALUES LESS THAN (-820000) ENGINE = InnoDB,
PARTITION p4 VALUES LESS THAN (-800000) ENGINE = InnoDB,
PARTITION p5 VALUES LESS THAN (-780000) ENGINE = InnoDB,
PARTITION p6 VALUES LESS THAN (-760000) ENGINE = InnoDB,
PARTITION p7 VALUES LESS THAN (-740000) ENGINE = InnoDB,
PARTITION p8 VALUES LESS THAN (-720000) ENGINE = InnoDB,
PARTITION p9 VALUES LESS THAN (-700000) ENGINE = InnoDB,
PARTITION p10 VALUES LESS THAN (-680000) ENGINE = InnoDB,
PARTITION p11 VALUES LESS THAN (-660000) ENGINE = InnoDB,
PARTITION p12 VALUES LESS THAN (-640000) ENGINE = InnoDB,
PARTITION p13 VALUES LESS THAN (-620000) ENGINE = InnoDB,
PARTITION p14 VALUES LESS THAN (-600000) ENGINE = InnoDB,
PARTITION p15 VALUES LESS THAN (-580000) ENGINE = InnoDB,
PARTITION p16 VALUES LESS THAN (-560000) ENGINE = InnoDB,
PARTITION p17 VALUES LESS THAN (-540000) ENGINE = InnoDB,
PARTITION p18 VALUES LESS THAN (-520000) ENGINE = InnoDB,
PARTITION p19 VALUES LESS THAN (-500000) ENGINE = InnoDB,
PARTITION p20 VALUES LESS THAN (-480000) ENGINE = InnoDB,
PARTITION p21 VALUES LESS THAN (-460000) ENGINE = InnoDB,
PARTITION p22 VALUES LESS THAN (-440000) ENGINE = InnoDB,
PARTITION p23 VALUES LESS THAN (-420000) ENGINE = InnoDB,
PARTITION p24 VALUES LESS THAN (-400000) ENGINE = InnoDB,
PARTITION p25 VALUES LESS THAN (-380000) ENGINE = InnoDB,
PARTITION p26 VALUES LESS THAN (-360000) ENGINE = InnoDB,
PARTITION p27 VALUES LESS THAN (-340000) ENGINE = InnoDB,
PARTITION p28 VALUES LESS THAN (-320000) ENGINE = InnoDB,
PARTITION p29 VALUES LESS THAN (-300000) ENGINE = InnoDB,
PARTITION p30 VALUES LESS THAN (-280000) ENGINE = InnoDB,
PARTITION p31 VALUES LESS THAN (-260000) ENGINE = InnoDB,
PARTITION p32 VALUES LESS THAN (-240000) ENGINE = InnoDB,
PARTITION p33 VALUES LESS THAN (-220000) ENGINE = InnoDB,
PARTITION p34 VALUES LESS THAN (-200000) ENGINE = InnoDB,
PARTITION p35 VALUES LESS THAN (-180000) ENGINE = InnoDB,
PARTITION p36 VALUES LESS THAN (-160000) ENGINE = InnoDB,
PARTITION p37 VALUES LESS THAN (-140000) ENGINE = InnoDB,
PARTITION p38 VALUES LESS THAN (-120000) ENGINE = InnoDB,
PARTITION p39 VALUES LESS THAN (-100000) ENGINE = InnoDB,
PARTITION p40 VALUES LESS THAN (-80000) ENGINE = InnoDB,
PARTITION p41 VALUES LESS THAN (-60000) ENGINE = InnoDB,
PARTITION p42 VALUES LESS THAN (-40000) ENGINE = InnoDB,
PARTITION p43 VALUES LESS THAN (-20000) ENGINE = InnoDB,
PARTITION p44 VALUES LESS THAN (0) ENGINE = InnoDB,
PARTITION p45 VALUES LESS THAN (20000) ENGINE = InnoDB,
PARTITION p46 VALUES LESS THAN (40000) ENGINE = InnoDB,
PARTITION p47 VALUES LESS THAN (60000) ENGINE = InnoDB,
PARTITION p48 VALUES LESS THAN (80000) ENGINE = InnoDB,
PARTITION p49 VALUES LESS THAN (100000) ENGINE = InnoDB,
PARTITION p50 VALUES LESS THAN (120000) ENGINE = InnoDB,
PARTITION p51 VALUES LESS THAN (140000) ENGINE = InnoDB,
PARTITION p52 VALUES LESS THAN (160000) ENGINE = InnoDB,
PARTITION p53 VALUES LESS THAN (180000) ENGINE = InnoDB,
PARTITION p54 VALUES LESS THAN (200000) ENGINE = InnoDB,
PARTITION p55 VALUES LESS THAN (220000) ENGINE = InnoDB,
PARTITION p56 VALUES LESS THAN (240000) ENGINE = InnoDB,
PARTITION p57 VALUES LESS THAN (260000) ENGINE = InnoDB,
PARTITION p58 VALUES LESS THAN (280000) ENGINE = InnoDB,
PARTITION p59 VALUES LESS THAN (300000) ENGINE = InnoDB,
PARTITION p60 VALUES LESS THAN (320000) ENGINE = InnoDB,
PARTITION p61 VALUES LESS THAN (340000) ENGINE = InnoDB,
PARTITION p62 VALUES LESS THAN (360000) ENGINE = InnoDB,
PARTITION p63 VALUES LESS THAN (380000) ENGINE = InnoDB,
PARTITION p64 VALUES LESS THAN (400000) ENGINE = InnoDB,
PARTITION p65 VALUES LESS THAN (420000) ENGINE = InnoDB,
PARTITION p66 VALUES LESS THAN (440000) ENGINE = InnoDB,
PARTITION p67 VALUES LESS THAN (460000) ENGINE = InnoDB,
PARTITION p68 VALUES LESS THAN (480000) ENGINE = InnoDB,
PARTITION p69 VALUES LESS THAN (500000) ENGINE = InnoDB,
PARTITION p70 VALUES LESS THAN (520000) ENGINE = InnoDB,
PARTITION p71 VALUES LESS THAN (540000) ENGINE = InnoDB,
PARTITION p72 VALUES LESS THAN (560000) ENGINE = InnoDB,
PARTITION p73 VALUES LESS THAN (580000) ENGINE = InnoDB,
PARTITION p74 VALUES LESS THAN (600000) ENGINE = InnoDB,
PARTITION p75 VALUES LESS THAN (620000) ENGINE = InnoDB,
PARTITION p76 VALUES LESS THAN (640000) ENGINE = InnoDB,
PARTITION p77 VALUES LESS THAN (660000) ENGINE = InnoDB,
PARTITION p78 VALUES LESS THAN (680000) ENGINE = InnoDB,
PARTITION p79 VALUES LESS THAN (700000) ENGINE = InnoDB,
PARTITION p80 VALUES LESS THAN (720000) ENGINE = InnoDB,
PARTITION p81 VALUES LESS THAN (740000) ENGINE = InnoDB,
PARTITION p82 VALUES LESS THAN (760000) ENGINE = InnoDB,
PARTITION p83 VALUES LESS THAN (780000) ENGINE = InnoDB,
PARTITION p84 VALUES LESS THAN (800000) ENGINE = InnoDB,
PARTITION p85 VALUES LESS THAN (820000) ENGINE = InnoDB,
PARTITION p86 VALUES LESS THAN (840000) ENGINE = InnoDB,
PARTITION p87 VALUES LESS THAN (860000) ENGINE = InnoDB,
PARTITION p88 VALUES LESS THAN (880000) ENGINE = InnoDB,
PARTITION p89 VALUES LESS THAN MAXVALUE ENGINE = InnoDB) */
- ID(标识符)
- 城市
- 邮政编码
- 纬度
- 经度
根据这篇文章和其他相关阅读,我有一个存储过程可以给出距离某个点(纬度/经度)最近的n个城镇或邮政编码。
我的存储过程:
BEGIN
DECLARE _deg2rad DOUBLE DEFAULT PI()/1800000;
SET @my_lat := _my_lat,
@my_lon := _my_lon,
@deg2dist := 0.0111325,
@start_deg := _start_dist / @deg2dist,
@max_deg := _max_dist / @deg2dist,
@cutoff := @max_deg / SQRT(2),
@dlat := @start_deg,
@lon2lat := COS(_deg2rad * @my_lat),
@iterations := 0;
SET @sql = CONCAT(
"SELECT COUNT(*) INTO @near_ct
FROM geoData
WHERE lat BETWEEN @my_lat - @dlat
AND @my_lat + @dlat
AND lon BETWEEN @my_lon - @dlon
AND @my_lon + @dlon");
PREPARE _sql FROM @sql;
MainLoop: LOOP
SET @iterations := @iterations + 1;
SET @dlon := ABS(@dlat / @lon2lat);
SET @dlon := IF(ABS(@my_lat) + @dlat >= 900000, 3600001, @dlon);
EXECUTE _sql;
IF ( @near_ct >= _limit OR
@dlat >= @cutoff ) THEN
LEAVE MainLoop;
END IF;
SET @dlat := LEAST(2 * @dlat, @cutoff);
END LOOP MainLoop;
DEALLOCATE PREPARE _sql;
SET @dlat := IF( @dlat >= @max_deg OR @dlon >= 1800000,
@max_deg,
GCDist(ABS(@my_lat), @my_lon,
ABS(@my_lat) - @dlat, @my_lon - @dlon) );
SET @dlon := IFNULL(ASIN(SIN(_deg2rad * @dlat) /
COS(_deg2rad * @my_lat))
/ _deg2rad
, 3600001);
IF (ABS(@my_lon) + @dlon < 1800000 OR
ABS(@my_lat) + @dlat < 900000) THEN
SET @sql = CONCAT(
"SELECT *,
@deg2dist * GCDist(@my_lat, @my_lon, lat, lon) AS dist
FROM geoData
WHERE lat BETWEEN @my_lat - @dlat
AND @my_lat + @dlat
AND lon BETWEEN @my_lon - @dlon
AND @my_lon + @dlon
HAVING dist <= ", _max_dist, "
ORDER BY dist
LIMIT ", _limit
);
ELSE
SET @west_lon := IF(@my_lon < 0, @my_lon, @my_lon - 3600000);
SET @east_lon := @west_lon + 3600000;
SET @sql = CONCAT(
"( SELECT *,
@deg2dist * GCDist(@my_lat, @west_lon, lat, lon) AS dist
FROM geoData
WHERE lat BETWEEN @my_lat - @dlat
AND @my_lat + @dlat
AND lon BETWEEN @west_lon - @dlon
AND @west_lon + @dlon
HAVING dist <= ", _max_dist, " )
UNION ALL
( SELECT *,
@deg2dist * GCDist(@my_lat, @east_lon, lat, lon) AS dist
FROM geoData
WHERE lat BETWEEN @my_lat - @dlat
AND @my_lat + @dlat
AND lon BETWEEN @east_lon - @dlon
AND @east_lon + @dlon
HAVING dist <= ", _max_dist, " )
ORDER BY dist
LIMIT ", _limit
);
END IF;
PREPARE _sql FROM @sql;
EXECUTE _sql;
DEALLOCATE PREPARE _sql;
END
我的问题:
我想输入一个邮编或城镇名称并从那里开始搜索。所以我的想法是请求这些信息,然后查找全球所有城镇/邮政编码的表。之后,如果只找到一个结果,我就有了纬度/经度的信息,否则我会要求用户在有多个结果的情况下选择正确的选项。
之后,我开始搜索离我当前位置最近的城镇。假设我想要一个50个城镇/市的列表。然后,我会查找并看看包含位置的表中是否有5个匹配结果。
再想一想,这听起来像是个坏主意...
方法1:
我研究了存储过程、SQL和大型查询,并尝试获得以下内容:
通过传递邮政编码/城市名称,我会查找它,从巨大的表中获取我的纬度/经度(可能作为mysql函数),然后在那里寻找最近的城镇,并立即加入位置表,获取我的5个最接近的位置。
问题:
- 如何避免同一城市/邮政编码名称的多个匹配?
- 使用简单的联接可以获取5个最接近的位置吗?
方法2:
获取所有位置的纬度/经度值,然后在此表上运行该过程。只使用巨大的表来检索我的当前位置?
这样,我需要收集所有位置的纬度/经度。但这可能是最好的方法。
但是,仅为了获取位置而拥有所有城市/邮政编码的巨大数据库似乎有点过头了。我希望还有其他替代方案...某种方式...
方法3:
老实说,我想要的这个函数似乎已经写了无数次。那么我为什么要费心重新发明轮子呢?但我不知道如何找到正确的文章或书籍来完成我的目标。
你们中有没有人对这样的最佳实践有任何想法?