This has both postgres and postgis included. You need to enable postgis by running the following statements

Transcription

1 1 Lab 0 (2016) Installing Initial Software for Spatial Databases Course Lecturer Pat Browne This note describes how to install some of the course software on Windows 7. Lab0 only covers installation for Windows 7. I will post advice for Windows 8+, Linux, and Mac users. 1) Install PostgreSQL 2) Install PostGIS. 3) Load spatial data into PostgreSQL/PostGIS from DOS command prompt 4) Load spatial data into PostgreSQL/PostGIS using PgAdmin 5) Install OpenJump a desktop geographical system. 6) Query spatial data using OpenJump as the graphical client. All installation and data files are stored in studentdisrib Advice for Windows 8+Mac users (Thanks to Carl Murphy). There is version of Postgres 8.4 which can be installed on Windows 8+ For users of Windows 8 or above: if you have probles with 8.4 then download the latest version of Postgres and enable PostGIS2.X Advice for Mac users (Thanks to Harold Hainsworth). here the steps that should have you up and running on a Mac. First download This has both postgres and postgis included. You need to enable postgis by running the following statements

2 2 They can be found at (They won't all run, not sure why, but the PostGIS ones do) Download PGAdmin Download OpenJump - OpenJUMP-Installer r4795-CORE.jar at: Harold followed the steps outlined in Lab0 and everything works much the same except the loading the county.sql file which is done via pgadmin 2. In PG Admin 3 connect to the correct db and then Click on Plugins/PSQL Console Write \i /path/to/yourfile.sql Press enter 1) Install PostgeSQL on Windows 7. Install from postgresql windows.exe Follow the dialogs, using defaults. You should use the password postgres for the super user postgres. Do not launch the StackBuilder.

3 3 1.1) Open the text interface to PostgreSQL From the Windows Start menu open PostgreSQL s command window/prompt with: All Programs PostGreSQL8.4 SQL Shell (psql) Accept default server, database, port, and user name. Password is postgres (ignore warning). Examine the output of the following commands: \h -- for help with SQL commands \? -- for help with psql commands \l -- for listing of databases All the above should give results from the default postgres database. \q -- the quit command, don t quit yet 1.2) Create a simple table and query in SQL Shell (psql) We will create, query, and drop a table. Make sure you have QuickEdit set so that you can copy and paste into the Shell. create table test ( t integer); \d \d test

4 4 insert into test(t) values(3) ; select * from test; drop table test; \d 2) Install PostGIS PostGIS is the spatial extension for PostgreSQL. From studentdisrib click on postgis-pg84-setup exe Accept defaults. The password should be postgres from previous step. This step will make a spatially enabled database called postgis. 2.1) Check PostGIS installation When PostGIS is install you should connect to the new database called postgis. The command \c connects to the new spatial database called postgis. Type the command \df to list the available functions (press q to stop output). Open the PostgreSQL administration tool called pgadmin III from the main Windows Start Menu. If you expand the Object Browser you should see the PostGIS database as below. Explore to see a list of spatial functions. The PostGIS manual is at: 3 Load spatial data into PostgreSQL/PostGIS from DOS command prompt

5 5 To load data we interact with PostgreSQL at command prompt level from outside the DBMS. Change directory (cd) in the command prompt: cd C:\Program Files (x86)\postgresql\8.4\bin Your screen should look like this: We will now load a SQL file containing spatial data. Examine county.sql using TextPad or Notepad. You should get familiar with the basics of an SQL file containing spatial data. At PostgreSQL bin command line, load counties into PostgreSQL, you may be prompted for a password (postgres). psql -d postgis -U postgres -f county.sql This command should be pasted into the Command Prompt Window (not the SQL Shell). The command will create a county table in the postgis database. If all goes well you should see a number of INSERT statements. To check that the data was loaded type the following in the SQL Shell(psql): select name from county; Note that the SQL Shell (psql) in black below is distinct from Command Prompt as shown in white below (your system will not have different colours). Now perform two text based queries in SQL shell select name from county; In SQL Shell (psql) you should still be connected to postgis. Type the following: \dt county You should see the county table created by the psql command in the previous section.

6 6 Note and index and constraints were automatically created. Note the_geom is the column where the geometry is stored. Geometry is generally only meaningful when rendered and viewed graphically. It is not a good idea to query raw geometry in a text interface. However we can run some queries in a text window: select name, km2, area_km2 from county; Here we query the non-spatial stored data. The columns km2 and area_km2 are the stored value of the perimeter and area respectively. We will now compare the calculated and stored values of the border of Meath: select name from county where name ilike '%County Borough' select km2 from county where name = 'Meath'; select st_perimeter(the_geom) from county where name = 'Meath'; select sum(st_area(the_geom))/ as sq Kms from county AS c where c.name like '%Dublin%'; select find_srid('public', 'county', 'the_geom'); select st_srid(the_geom) from county where name = 'Meath'; 4) Load spatial data into PostgreSQL/PostGIS from DOS command prompt This method of loading spatial is suitable for both Mac and Windows. Download the county.sql file into a folder, assume c:\dt249spatialdatabases. Start pgadmin and navigate to the database where you wish to load the data. In this case it will be the postgis database as below: Open the SQL window and open the county.sql file. Notice the BEGIN; and END; include a semicolon (;) which must be removed. The easiest way to do this is to use the replace function in the editor. Replace BEGIN; and END; with BEGIN and END respectively.

7 7 Next run the SQL script with the run button: The county table should now be loaded into Postgres/PostGIS Run the following to check this: select name from county; To run a single query (as opposed to a script) you should open a new query window type in the query. You should highlight the query and press the green execute button as above. 5) Install OpenJump OpenJump GIS can act as a client for PostgreSQL/PostGIS. SQL queries can be issued and viewed directly from OpenJump. If updated data is required in the database for later use, then the user must explicitly create a table from the result set. Changes to data in OpenJump are not reflected back to the database. Note all displayed spatial geometry viewed in OpenJump needs to be cast asbinary in the SQL. Download and install OpenJUMP r4164-CORE from: The OpenJump home page is at: 6) Query PostgreSQL/PosGIS tables in OpenJump We can add a complete PostGIS table as an OpenJump Layer as follows: File Open Add Datastore Layer Click on the icon to the right of connection

8 8 Make a new connection: When the connection is made, click on the Dataset dropdown. The Geometry dropdown is automatically filled with the_geom, which is the standard name for the geometry column in PostgreSQL/PostGIS. Click OK. OpenJump should retrieve following map from PostgreSQL/PostGIS.

9 9 Display a PostgreSQL/PostGIS query result in OpenJump From the main OpenJump menu select File Run Datastore Query. Enter the following in the dialog box: select name,st_asbinary(the_geom) from county where name = 'Meath' You should see Meath highlighted. Note we are using OpenJump as a viewer, any changes made in OpenJump are not reflected in the database. To view the name the style needs to be changed as follows:

10 10 Wimdows 8+ Mac