diff options
| -rw-r--r-- | db/migrate_from_osgb36_to_wgs84.pl | 116 | ||||
| -rw-r--r-- | db/schema.sql | 10 |
2 files changed, 121 insertions, 5 deletions
diff --git a/db/migrate_from_osgb36_to_wgs84.pl b/db/migrate_from_osgb36_to_wgs84.pl new file mode 100644 index 000000000..462061281 --- /dev/null +++ b/db/migrate_from_osgb36_to_wgs84.pl @@ -0,0 +1,116 @@ +#!/usr/bin/env perl + +use strict; +use warnings; + +=head1 DESCRIPTION + +This script will take a FMS database with eastings and northings in and migrate +it to latitude and longitude. It touches the following tables and functions: + +=cut + +use FindBin; +use lib "$FindBin::Bin/../perllib"; +use lib "$FindBin::Bin/../commonlib/perllib"; + +use mySociety::Config; +use mySociety::DBHandle qw(dbh); +use mySociety::GeoUtil qw(national_grid_to_wgs84); + +BEGIN { + mySociety::Config::set_file("$FindBin::Bin/../conf/general"); + mySociety::DBHandle::configure( + Name => mySociety::Config::get('BCI_DB_NAME'), + User => mySociety::Config::get('BCI_DB_USER'), + Password => mySociety::Config::get('BCI_DB_PASS'), + Host => mySociety::Config::get( 'BCI_DB_HOST', undef ), + Port => mySociety::Config::get( 'BCI_DB_PORT', undef ) + ); +} + +migrate_problem_table(); + +=head2 problem table + +Add columns 'latitude' and 'longitude'. +Update all entries coverting from e,n to lon,lat. +Make the lat, lon columns not null. +Drop the 'problem_state_easting_northing_idx' index. +Create new index 'problem_state_latitude_longitude_idx'. +Drop the 'easting' and 'northing' columns. + +=cut + +sub migrate_problem_table { + + my $dbh = dbh(); + + # add columns + print "add latitude, longitude columns\n"; + $dbh->do("ALTER TABLE problem ADD $_ double precision") + for qw(latitude longitude); + $dbh->commit; + + # create a query for rows that need converting + my $rows_to_convert_query = $dbh->prepare( # + "SELECT id, easting, northing FROM problem" + . " WHERE latitude is NULL limit 1" # FIXME + ); + + # update query + my $update_lat_lon_query = $dbh->prepare( # + "UPDATE problem SET latitude = ?, longitude = ? WHERE id = ?" + ); + + # loop through the entries in batches updating rows that need it. Do this in + # Perl rather than SQL for conveniance. + while (1) { + $rows_to_convert_query->execute; + last unless $rows_to_convert_query->rows; + while ( my $r = $rows_to_convert_query->fetchrow_hashref ) { + my ( $latitude, $longitude ) = + _e_n_to_lat_lon( $r->{easting}, $r->{northing} ); + print "update problem $r->{id}: ( $latitude, $longitude )\n"; + $update_lat_lon_query->execute( $latitude, $longitude, $r->{id} ); + } + $dbh->commit; # every batch of updates + } + + # drop old index, create new one + print "drop and create indexes\n"; + $dbh->do("DROP INDEX problem_state_easting_northing_idx"); + $dbh->do( "CREATE INDEX problem_state_latitude_longitude_idx " + . "ON problem(state, latitude, longitude)" ); + $dbh->commit; + + # drop columns + print "drop easting, northing columns\n"; + $dbh->do("ALTER TABLE problem DROP $_") for qw(easting northing); + $dbh->commit; + +} + +=head2 problem_find_nearby function + +Convert to use lat and long. +Also swap parameter order so that it is lat,lon rather than lon,lat to be consistent with pledgebank etc + +=head2 alert table + +NOTE: only for alert_types 'local_problems' or 'local_problems_state' + +parameter: convert easting to longitude +parameter2: convert nothing to latitude + +=cut + +=head2 HELPERS + +=cut + +sub _e_n_to_lat_lon { + my ( $e, $n ) = @_; + my ( $lat, $lon ) = national_grid_to_wgs84( $e, $n, 'G' ); + return ( $lat, $lon ); +} diff --git a/db/schema.sql b/db/schema.sql index 53d188244..59aacce6e 100644 --- a/db/schema.sql +++ b/db/schema.sql @@ -121,8 +121,8 @@ create table problem ( -- Problem details postcode text not null, - easting double precision not null, - northing double precision not null, + latitude double precision not null, + longitude double precision not null, council text, -- the council(s) we'll report this problem to areas text not null, -- the voting areas this location is in category text not null default 'Other', @@ -155,7 +155,7 @@ create table problem ( whensent timestamp, send_questionnaire boolean not null default 't' ); -create index problem_state_easting_northing_idx on problem(state, easting, northing); +create index problem_state_latitude_longitude_idx on problem(state, latitude, longitude); create table questionnaire ( id serial not null primary key, @@ -277,8 +277,8 @@ create table alert_type ( create table alert ( id serial not null primary key, alert_type text not null references alert_type(ref), - parameter text, -- e.g. Problem ID for new updates - parameter2 text, -- e.g. Latitude for local problem alerts + parameter text, -- e.g. Problem ID for new updates, Easting for local problem alerts + parameter2 text, -- e.g. Northing for local problem alerts email text not null, confirmed integer not null default 0, lang text not null default 'en-gb', |