[nongnu] elpa/emacsql 9e6ea00f01 243/427: Add note about PostgreSQL.

[ELPA Syncer]

branch: elpa/emacsql
commit 9e6ea00f01b8dc85b7966e08c1625554764b97cb
Author: Christopher Wellons <wellons@nullprogram.com>
Commit: Christopher Wellons <wellons@nullprogram.com>

    Add note about PostgreSQL.
---
 README.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/README.md b/README.md
index ef009129bb..d9236aded4 100644
--- a/README.md
+++ b/README.md
@@ -309,6 +309,10 @@ and unit testing.
 
     make test
 
+If the environmental variable `PGDATABASE` is present then the unit
+tests will also be run with PostgreSQL in addition to SQLite. Also
+provide `PGHOST`, `PGPORT`, and `PGUSER` if needed.
+
 ### Creating a New Front-end
 
 Emacsql uses EIEIO so that interactions with a connection occur