Download Chapter 18

Mapping from a database
Peterson
Linux
• PHP and MySQL were largely developed under
Linux
– open source operating system based on UNIX
• Linus Torvalds –
– “Hello everybody out there! I'm doing a (free)
operating system … (just a hobby, won't be big
and professional) for 386(486) AT clones. This has
been brewing since april, and is starting to get
ready.I'd like any feedback.”
PHP and MySQL
• Most Linux installation procedures include the
option of installing PHP and MySQL.
• Administration of online databases is done
through phpMyAdmin
– Available through the cPanel
• Purpose of exercises:
– Develop familiarity with PHP
– Input and query MySQL tables
PHP Example 1
PHP example 2
PHP example 3
PHP example 4
PHP Example 5
PHP Example 6
PHP Example 7
PHP Example 8
cPanel
MySQL is used to define
new tables
SQL
Browse
Structure
SQL
Search
mysql_connect.php
All Capitals
//connection to database and querying
<?php
include 'mysql_connect.php';
$table = "us_capitals";
$sql = "SELECT name, usstate, population, Y(location), X(location) FROM $table";
$res = mysql_query($sql);
if($res){
$num = mysql_num_rows($res);
while($row = mysql_fetch_array($res)){
// contents one row of database
$lat = $row['X(location)'];
$lon = $row['Y(location)'];
$name = $row['name'];
$state = $row['usstate'];
$pop = $row['population'];
// create marker
echo 'var myLatlng = new google.maps.LatLng('.$lat.','.$lon.');';
echo 'var marker = new google.maps.Marker({position: myLatlng, map: map, title: "'.$name.', Popu
// info message will be attached
echo 'attachMessage(marker, "'.$name.'", "'.$state.'", "'.$pop.'");';
}
} else echo "alert('SQL-Error getting data from database...')";
mysql_close($conn);
?>
North of Omaha / less than 500,000
//connection to database and querying
<?php
include 'mysql_connect.php';
$table = "us_capitals";
$sql = "SELECT name, usstate, population, Y(location), X(location)
FROM $table WHERE X(location) > 41.25 AND population < 500000";
$res = mysql_query($sql);
Select within box
<?php
//define coordinates and draw rectangle to map
include 'mysql_connect.php';
$table = "us_capitals";
$sql =" SELECT name, Y(location), X(location), usstate, population FROM us_capitals
WHERE Intersects( location,
GeomFromText( 'POLYGON((40 -96, 44 -96, 44 -70, 40 -70, 40 -96))' ) ) ";
DROP TABLE IF EXISTS cities;
Part of the SQL code for entering
three tables that provide city
location, airport information, and
airline connections.
create table cities (
city VARCHAR(30),
location GEOMETRY NOT NULL,
SPATIAL INDEX(location),
PRIMARY KEY (city)
);
INSERT INTO cities (city, location) VALUES ("Omaha", GeomFromText('POINT(41.25 -96)'));
INSERT INTO cities (city, location) VALUES ("Atlanta", GeomFromText('POINT(33.755 -84.39)'));
INSERT INTO cities (city, location) VALUES ("Lincoln", GeomFromText('POINT(40.809722 -96.675278)'));
DROP TABLE IF EXISTS dl_airports;
create table dl_airports (
city VARCHAR(30),
airport VARCHAR(30),
code VARCHAR(3),
FOREIGN KEY (city) REFERENCES cities(city),
PRIMARY KEY (code)
);
INSERT INTO dl_airports (city, airport, code) VALUES ("Omaha","Omaha Eppley Airfield", "OMA");
INSERT INTO dl_airports (city, airport, code) VALUES ("Atlanta","Hartsfield-Jackson International Airport", "ATL");
INSERT INTO dl_airports (city, airport, code) VALUES ("Lincoln","Municipal Airport", "LNK");
DROP TABLE IF EXISTS dl_routes;
create table dl_routes (
airportCode VARCHAR(3),
destinationCode VARCHAR(3),
FOREIGN KEY (airportCode) references dl_airports(code),
FOREIGN KEY (destinationCode) references dl_airports(code)
);
INSERT INTO dl_routes (airportCode, destinationCode) VALUES ("OMA","ATL");
INSERT INTO dl_routes (airportCode, destinationCode) VALUES ("OMA","DET");
INSERT INTO dl_routes (airportCode, destinationCode) VALUES ("OMA","MEM");
Flight Routes
<?php
include 'mysql_connect.php';
$sql = "SELECT cDep.city AS departure , X( cDep.location ) AS latDep , Y( cDep.location ) AS lngDep, cDst.city AS destination ,
X( cDst.location ) AS latDest, Y( cDst.location ) AS lngDest
FROM (
(
(
dl_routes AS rt
INNER JOIN dl_airports AS ap1 ON rt.airportcode = ap1.code
)
INNER JOIN dl_airports AS ap2 ON rt.destinationcode = ap2.code
)
INNER JOIN cities AS cDep ON cDep.city = ap1.city_name
)
INNER JOIN cities AS cDst ON cDst.city = ap2.city_name";
$res = mysql_query($sql);
if($res){
$num = mysql_num_rows($res);
while($row = mysql_fetch_array($res)){
echo "var flightPlanCoordinates = [
new google.maps.LatLng(".$row['latDep'].", ".$row['lngDep']."),
new google.maps.LatLng(".$row['latDest'].", ".$row['lngDest'].")
];
flightPath = new google.maps.Polyline({
path: flightPlanCoordinates,
strokeColor: \"#FF0000\",
strokeOpacity: 0.8,
geodesic: true,
strokeWeight: 1
});
flightPath.setMap(map);";
}
} else echo "alert('SQL-Error getting data from database...')";
mysql_close($conn);
?>
Selected routes
$sql = "SELECT cDep.city AS departure, X( cDep.location ) AS latDep, Y( cDep.location )
AS lngDep, cDst.city AS destination, X( cDst.location ) AS latDest,
Y( cDst.location ) AS lngDest
FROM (
(
(
dl_routes AS rt
INNER JOIN dl_airports AS ap1 ON rt.airportcode = ap1.code
)
INNER JOIN dl_airports AS ap2 ON rt.destinationcode = ap2.code
)
INNER JOIN cities AS cDep ON cDep.city = ap1.city_name
)
INNER JOIN cities AS cDst ON cDst.city = ap2.city_name
WHERE cDep.city = 'Omaha'";
$res = mysql_query($sql);
create table ne_counties (
strokecolor VARCHAR(7),
strokewidth INT(5),
strokeopacity FLOAT(5),
fillcolor VARCHAR(7),
fillopacity FLOAT(5),
popdata INT(15),
name VARCHAR(30),
geom GEOMETRY NOT NULL,
SPATIAL INDEX(geom)
);
MySQL commands, attributes, and
coordinates for placing two county
polygons for Nebraska into a MySQL
database.
INSERT INTO ne_counties (strokecolor, strokewidth , strokeopacity , fillcolor, fillopacity , popdata, name, geom) VALUES
("#008800",1,1.0,"#FFCC00",0.06674,33185,"county", GeomFromText('POLYGON((40.698311157 98.2829258865,40.698311157 -98.2781218448,40.3505519215 -98.2781218448,40.3500181391 98.3309663027,40.3504184759 -98.3344358884,40.3504184759 -98.7238301514,40.6413298855 98.7242304882,40.6897706386 -98.7244973794,40.6989783851 -98.7243639338,40.6991118307 98.7214281306,40.6985780482 -98.686198492,40.698311157 -98.2829258865, 40.698311157 -98.2829258865))'));
INSERT INTO ne_counties (strokecolor, strokewidth , strokeopacity , fillcolor, fillopacity , popdata, name, geom) VALUES
("#008800",1,1.0,"#FFCC00",0.01334,6931,"county", GeomFromText('POLYGON((41.9149346991 98.2956032185,42.0888143169 -98.2954697729,42.0888143169 -98.3004072602,42.3035282886 98.3005407058,42.4369738893 -98.300140369,42.4377745629 -97.8344152223,42.2326686746 97.8352158959,42.0897484361 -97.8346821135,42.0347688486 -97.8341483311,41.9164026008 97.8332142119,41.9152015904 -98.0647423292,41.9149346991 -98.2956032185, 41.9149346991 -98.2956032185))'));
Nebraska county polygons
//connection to database and querying
<?php
include 'mysql_connect.php';
$sql = "SELECT popdata, AsText(ExteriorRing(geom)) AS linestring FROM ne_counties;";
$res = mysql_query($sql);
// first statement -> get all polygons
if($res){
// loop through all polygons
while($row = mysql_fetch_array($res)){
$linestring = $row['linestring']; //points of current county polygon
$pop = $row['popdata']; //population of current county
//linestring includes all points of current polygon LINESTRING(40.698311157 98.2829258865,40.69831115...)
//delete not needed characters
$clearedLS = str_replace(array("LINESTRING(" , "," , ")"),array(""," ",""),$linestring);
//parse the string in PHP and store coordinates in array
$coordinates = explode(" ", $clearedLS);
//read coordinates from array by pair
//and finally create javascript GM latitude/longitude objects for polygons
echo "var pts = new Array();";
$j=0;
for ($i =0; $i<count($coordinates); $i=$i+2){
echo "pts[".$j."] = new
google.maps.LatLng(".$coordinates[$i].",".$coordinates[$i+1].");";
$j++;
}
echo "polygon = new google.maps.Polygon({
paths: pts,
strokeColor: '#0000FF',
strokeOpacity: 1.0,
strokeWeight: 0.5,
fillColor: '#0000FF',
fillOpacity: 0.4
});";
echo "polygon.setMap(map);";
}
} else echo "alert('SQL-Error getting data from database...')";
mysql_close($conn);
?>
Nebraska county population
// Find the min and max population values for the 93 counties after doing a
non-linear transformation using the log function
var min=100000000;
var max=-100000000;
for (var i = 0; i < 93; i++) {
// Log the data to deal with counties with large populations
popdata[i] = Math.log(popdata[i])
if (popdata[i] < min) { min=popdata[i] }
if (popdata[i] > max) { max=popdata[i] }
}
// Find the range and compute the opacities for each polygon
var range = max-min
// compute an opacity as a range of the data values
opacities = new Array ()
for (var i = 0; i < 93; i++) {
opacities[i] = 1-((max - popdata[i]) / range)
}
Counties with less than 50,000
$sql = "SELECT popdata, AsText(ExteriorRing(geom)) AS linestring
FROM ne_counties
WHERE popdata < 50000;";
$res = mysql_query($sql);
<?php
include 'mysql_connect.php';
$sql = "SELECT popdata, AsText( ExteriorRing( geom ) ) AS geom
FROM ne_counties
WHERE Intersects( GeomFromText( 'POINT(41.25 -96)' ) , geom )
OR Intersects( GeomFromText( 'POINT(40.809722 -96.675278)' ) , geom )
OR Intersects( GeomFromText( 'POINT(40.700833 -99.081111)' ) , geom )
";
$res = mysql_query($sql);