将纬度和经度值保存为字符串还是数字？

Question

关于我之前的问题：将纬度和经度值保存到MySQL数据库iOS

请问这段代码是否将我的纬度和经度值保存为字符串或数字。如果保存为字符串，您能告诉我如何保存为数字吗？

此外，我已经将它们在MySQL字段中设置为float类型。

PHP

<?php

$username = "username";
$database = "database";
$password = "password";

mysql_connect(localhost, $username, $password);

@mysql_select_db($database) or die("unable to find database");

$name = $_GET["name"];
$address = $_GET["address"];
$city = $_GET["city"];
$county = $_GET["county"];
$country = $_GET["country"];
$postcode = $_GET["postcode"];
$date = $_GET["date"];
$time = $_GET["time"];
$latitude = $_GET["latitude"];
$longitude = $_GET["longitude"];

$query = "INSERT INTO map VALUES ('', '$name', '$address', '$city', '$county', '$country', '$postcode', '$date', '$time', '$latitude', '$longitude')";

mysql_query($query) or die(mysql_error("error"));
mysql_close();

?>

AddSessionViewController.h

#import <UIKit/UIKit.h>

#define kpostURL @"http://myurl.com/map.php"
#define kname @"name"
#define kaddress @"address"
#define kcity @"city"
#define kcounty @"county"
#define kcountry @"country"
#define kpostcode @"postcode"
#define kdate @"date"
#define ktime @"time"
#define klatitude @"latitude"
#define klongitude @"longitude"

@interface addSessionViewController : UIViewController {

IBOutlet UITextField *nameText;
IBOutlet UITextField *addressText;
IBOutlet UITextField *cityText;
IBOutlet UITextField *countyText;
IBOutlet UITextField *countryText;
IBOutlet UITextField *postcodeText;
IBOutlet UITextField *dateText;
IBOutlet UITextField *timeText;
IBOutlet UITextField *latitudeText;
IBOutlet UITextField *longitudeText;
NSURLConnection *postConnection;

}

-(IBAction)post:(id)sender;
-(IBAction)getLatLon:(id)sender;


-(void) postMessage:(NSString*) postcode withName:(NSString *) name withAddress:(NSString *) address withCity:(NSString *) city withCounty:(NSString *) county withCountry:(NSString *) country  withDate:(NSString *) date withTime:(NSString *) time withLatitude:(NSString *) latitude withLongitude:(NSString *) longitude;

AddSessionViewController.m

-(void) postMessage:(NSString*) postcode withName:(NSString *) name withAddress:(NSString *) address withCity:(NSString *) city withCounty:(NSString *) county withCountry:(NSString *) country withDate:(NSString *) date withTime:(NSString *) time withLatitude:(NSString *)latitude withLongitude:(NSString *)longitude; {

if (name != nil && address != nil && city != nil && county != nil && country != nil && postcode !=nil && date != nil && time != nil && latitude != nil && longitude != nil){

    NSMutableString *postString = [NSMutableString stringWithString:kpostURL];

    [postString appendString:[NSString stringWithFormat:@"?%@=%@", kname, name]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", kaddress, address]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", kcity, city]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", kcounty, county]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", kcountry, country]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", kpostcode, postcode]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", kdate, date]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", ktime, time]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", klatitude, latitude]];

    [postString appendString:[NSString stringWithFormat:@"&%@=%@", klongitude, longitude]];

    [postString setString:[postString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:postString]];
    [request setHTTPMethod:@"POST"];

    postConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:YES];

}

}


-(IBAction)post:(id)sender{

[self postMessage:(NSString*) postcodeText.text withName:nameText.text withAddress:addressText.text withCity:cityText.text withCounty:countyText.text withCountry:countryText.text withDate:dateText.text withTime:timeText.text withLatitude:latitudeText.text withLongitude:longitudeText.text];

[postcodeText resignFirstResponder];
nameText.text = nil;
addressText.text = nil;
cityText.text = nil;
countyText.text = nil;
countryText.text = nil;
postcodeText.text = nil;
dateText.text = nil;
timeText.text = nil;
latitudeText.text = nil;
longitudeText.text = nil;
[[NSNotificationCenter defaultCenter] postNotificationName:@"Test2" object:self];
}


-(IBAction)getLatLon:(id)sender{


NSString *eventName = [nameText text];
NSString *eventAddress = [addressText text];
NSString *eventCity = [cityText text];
NSString *eventCountry = [countryText text];
NSString *eventCounty = [countyText text];
NSString *eventDate = [dateText text];
NSString *eventPostCode = [postcodeText text];
NSString *eventTime = [timeText text];

// Use this to build the full event string
NSString *addressString = [NSString stringWithFormat:@"%@,%@,%@,%@,%@,%@,%@,%@", eventName, eventAddress, eventCity, eventCounty, eventCountry, eventPostCode, eventDate, eventTime];

// A search can't inlude the event and time and hour as it means nothing to MapKit
// The geocodeAddressString simply contains the address info
NSString *geocodeAddressString = [NSString stringWithFormat:@"%@,%@,%@,%@,%@", eventAddress, eventCity, eventCounty, eventCountry, eventPostCode];

//NSLog(@"Hello %@",addressString);
CLGeocoder *geocoder = [[CLGeocoder alloc] init]; 

[geocoder geocodeAddressString:geocodeAddressString completionHandler:^(NSArray* placemarks, NSError* error){
    // Check for returned placemarks
    if (placemarks && placemarks.count > 0) {
        CLPlacemark *topResult = [placemarks objectAtIndex:0];

        //NSLog([topResult locality]);
        //NSLog([topResult location]);
        //MKCoordinateRegion region;
        //double *value = topResult.region.center.latitude;

        CLLocationDegrees latitude = topResult.region.center.latitude;
        CLLocationDegrees longitude = topResult.location.coordinate.longitude;

        NSString *latitudeString = [NSString stringWithFormat:@"%f",latitude];
        NSString *longitudeString = [NSString stringWithFormat:@"%f",longitude];

        latitudeText.text = latitudeString;
        longitudeText.text = longitudeString;

        NSLog(@"Lat: %f", latitude);
        NSLog(@"Long: %f", longitude);
    }
}];
}

- krisscross90

---

请将这段代码精简至关键部分。 - undefined

Answer 1

如果一个城市名中有撇号，会发生什么？您可能需要查看mysql_real_escape_string。

无论如何，它们将被存储为浮点数。数据始终以列的数据类型存储（除非您将null视为数据类型:p）。

如果经度和纬度是浮点数，则查询中的引号实际上是不必要的（尽管在删除引号之前，您需要确保它们实际上是浮点数，否则您将打开SQL注入漏洞）。

现在将发生的是，当执行查询时，MySQL将默默地将字符串转换为浮点值。

- Corbin

---

非常感谢您的快速回复，Corbin！我目前正在尝试将一个地图工具教程适应到我的地图视图上，以显示我在数据库中存储的地址作为标注。但是我无法使其正常工作，所以我以为可能是这个原因，但我猜想问题出在我的其他代码上 :) 我也会研究一下mysql_real_escape_string！ - undefined

没问题。而且你绝对应该这样做（还有防止 SQL 注入）。真是可惜有这么多 PHP/MySQL 教程完全忽视了在 SQL 中正确转义字符串的方法 x.x. - undefined

Answer 2

它们将以数据库字段的格式保存。因此，如果您使用的是"int"，它们将被转换为整数；如果您使用的是float，它们将四舍五入为最接近的浮点数；如果您将其设置为VarChar，则将保存为字符串。

要保存为数字，请将表结构中的字段类型转换为数字 - 假设您已经验证了输入是否为数字，那么相同的SQL查询就足够了（但在其他人指出之前可能需要改进 :) ）

- Robbie