Add execute()

qc0/__init__.py

@@ -1,10 +1,29 @@
+import sqlalchemy as sa
+
 from .syn import Q, q
 from .syn_to_op import syn_to_op
 from .op_to_sql import op_to_sql
+from .scope import Cardinality
 
 __version__ = "0.1.0"
 
-__all__ = ("parse", "Q", "q", "syn_to_op", "op_to_sql")
+__all__ = ("execute", "parse", "Q", "q", "syn_to_op", "op_to_sql")
+
+
+def execute(query, meta: sa.MetaData, engine: sa.engine.Engine):
+    """ Execute query."""
+    if isinstance(query, Q):
+        query = query.syn
+    elif isinstance(query, str):
+        query = parse(query)
+    op = syn_to_op(query, meta)
+    sql = op_to_sql(op)
+    with engine.connect() as conn:
+        res = conn.execute(sql)
+        value = [row.value for row in res.fetchall()]
+        if op.card != Cardinality.SEQ:
+            value = value[0]
+        return value
 
 
 def parse(q):

qc0/cli.py

@@ -6,19 +6,15 @@
 def shell(db):
     from IPython.terminal.embed import embed
     from sqlalchemy import create_engine, MetaData
-    from qc0 import Q as BaseQ, syn_to_op, op_to_sql
+    from qc0 import Q as BaseQ, execute
 
     engine = create_engine(db)
     meta = MetaData()
     meta.reflect(bind=engine)
 
     class Q(BaseQ):
         def run(self):
-            op = syn_to_op(self.syn, meta)
-            sql = op_to_sql(op)
-            with engine.connect() as conn:
-                res = conn.execute(sql)
-                return [row[0] for row in res.fetchall()]
+            return execute(self, meta, engine)
 
     q = Q(None)  # NOQA