updates

research/ext_lib/db.py

@@ -0,0 +1,39 @@
+"""Database-related stuff"""
+
+import sqlalchemy
+from sqlalchemy import create_engine, text
+
+DB_USER = "postgres"
+DB_PW = "KzsZ0wz5tp2wUIPM"
+DB_HOST = "db.stratlab.dev"
+DB_PORT = 30543
+DB_URL = f"postgresql://{DB_USER}:{DB_PW}@{DB_HOST}:{DB_PORT}"
+print(DB_URL)
+#DB_ARGS = {"sslmode": "verify-full", "sslrootcert": "system"}
+DB_ARGS = {}
+
+def db_connect(db_name: str) -> sqlalchemy.engine.Engine:
+    """Connect to DB. Create it if it doesn't exist
+    Args:
+        db_name: name of the database to create
+    """
+    try:
+        engine = create_engine(f"{DB_URL}/{db_name}", connect_args=DB_ARGS)
+        engine.connect()
+        return engine
+    except sqlalchemy.exc.OperationalError:
+        # Database doesn't exist, create it
+        conn = create_engine(f"{DB_URL}/postgres", isolation_level="AUTOCOMMIT", connect_args=DB_ARGS).connect()
+        # TODO: figure out how to get rid of SQL injection. Standard parameterization adds quotes that breaks syntax
+        conn.execute(text(f"CREATE DATABASE {db_name}"))
+
+        return create_engine(f"{DB_URL}/{db_name}", connect_args=DB_ARGS)
+
+
+# list exchanges
+# list symbols
+# first date
+# last date
+
+# get data
+# save data