Postgres test instructions

README.md

@@ -240,3 +240,34 @@ There are many differences between SQL syntax and functions supported by differe
 - PostgreSQL: `Database.Esqueleto.PostgreSQL`
 
 In order to use these functions, you need to explicitly import their corresponding modules.
+
+
+### Tests and Postgres
+
+To ```stack test``` with Postgresql you'll need to set the Postgres flag to true in esqueleto.cabal 
+
+```Flag postgresql
+  Description: test postgresql. default is to test sqlite.
+Default: False```
+
+If you don't have Postgres install it. Using apt-get it's just:
+
+```sudo apt-get install postgresql postgresql-contrib
+sudo apt-get install libpq-dev```
+
+The connection details are located near the bottom of the test/Test.hs file:
+
+```#if defined(WITH_POSTGRESQL)
+withPostgresqlConn "host=localhost port=5432 user=esqutest password=esqutest dbname=esqutest"```
+
+You can change these if you like but to just get them working set up as follows:
+
+```$ sudo -u postgres createuser esqutest```
+
+```$ sudo -u postgres createdb esqutest```
+
+```$ sudo -u postgres psql
+postgres=# \password esqutest
+```
+
+Now ```stack test``` should envoke and pass all the Postgres tests.