BUG: Postgres 10 failing on regex_extract

appveyor.yml

@@ -6,14 +6,23 @@ platform:
 environment:
   PGUSER: "postgres"
   PGPASSWORD: "Password12!"
+  PGPORT: 5432
+  PGHOST: "localhost"
+
   IBIS_TEST_DOWNLOAD_DIRECTORY: "%USERPROFILE%"
   IBIS_TEST_DOWNLOAD_BASE_URL: "https://storage.googleapis.com/ibis-ci-data"
   IBIS_TEST_DOWNLOAD_NAME: "ibis-testing-data.tar.gz"
+
   IBIS_TEST_DATA_DIRECTORY: "%USERPROFILE%\\ibis-testing-data"
+
   IBIS_TEST_POSTGRES_USER: "%PGUSER%"
   IBIS_TEST_POSTGRES_PASSWORD: "%PGPASSWORD%"
+  IBIS_TEST_POSTGRES_PORT: "%PGPORT%"
+  IBIS_TEST_POSTGRES_HOST: "%PGHOST%"
   IBIS_TEST_POSTGRES_DATABASE: "ibis_testing"
+
   IBIS_TEST_SQLITE_DATABASE: "%USERPROFILE%\\ibis_testing.db"
+
   CONDA: "C:\\Miniconda36-x64\\Scripts\\conda"
   ACTIVATE: "C:\\Miniconda36-x64\\Scripts\\activate"
 
@@ -24,9 +33,11 @@ environment:
     - PYTHON_VERSION: "3.6"
 
 services:
-  - postgresql93
+  - postgresql10
 
 test_script:
+  - "net start postgresql-x64-10"  # workaround until https://help.appveyor.com/discussions/problems/11031-postgresql-10-service-not-starting is resolved
+  - "\"C:\\Program Files\\PostgreSQL\\10\\bin\\psql\" -c \"SELECT VERSION()\""
   - "%CONDA% --version"
   - "%CONDA% config --set always_yes true"
   - "%CONDA% install conda=4.3.22 --channel conda-forge"

ibis/sql/postgres/compiler.py

@@ -444,11 +444,12 @@ def __init__(self, string, pattern, index):
 
 @compiles(regex_extract, 'postgresql')
 def compile_regex_extract(element, compiler, **kw):
-    return '(REGEXP_MATCHES(%s, %s))[%s]' % (
+    result = '(SELECT * FROM REGEXP_MATCHES({}, {}))[{}]'.format(
         compiler.process(element.string, **kw),
         compiler.process(element.pattern, **kw),
         compiler.process(element.index, **kw),
     )
+    return result
 
 
 def _regex_extract(t, expr):

ibis/sql/postgres/tests/conftest.py

@@ -30,6 +30,10 @@
     'IBIS_TEST_POSTGRES_HOST',
     os.environ.get('PGHOST', 'localhost')
 )
+PG_PORT = os.environ.get(
+    'IBIS_TEST_POSTGRES_PORT',
+    os.environ.get('PGPORT', 5432)
+)
 IBIS_TEST_POSTGRES_DB = os.environ.get(
     'IBIS_TEST_POSTGRES_DATABASE',
     os.environ.get('PGDATABASE', 'ibis_testing')
@@ -43,6 +47,7 @@ def con():
         user=PG_USER,
         password=PG_PASS,
         database=IBIS_TEST_POSTGRES_DB,
+        port=PG_PORT,
     )