Fix SQL and empty queries (#5776)

edb/common/debug.py

@@ -165,6 +165,15 @@ class flags(metaclass=FlagsMeta):
             "Requires pydebug to be installed."
     )
 
+    sql_input = Flag(
+        doc="Enable logging of SQL incoming requests (pg compiler input)."
+    )
+
+    sql_output = Flag(
+        doc="Enable logging of SQL requests, compiled to the internal SQL"
+            "(pg compiler output)."
+    )
+
 
 @contextlib.contextmanager
 def timeit(title='block'):

edb/server/compiler/compiler.py

@@ -576,6 +576,13 @@ def compute_stmt_name(text: str) -> str:
         sql_units = []
         for stmt in stmts:
             orig_text = pg_gen_source(stmt)
+
+            if debug.flags.sql_input:
+                debug.header('SQL Input')
+                debug.dump_code(
+                    pg_codegen.generate_source(stmt, pretty=True), lexer='sql'
+                )
+
             unit_ctor = functools.partial(
                 dbstate.SQLQueryUnit,
                 orig_query=orig_text,
@@ -765,14 +772,22 @@ def compute_stmt_name(text: str) -> str:
                     translation_data=source.translation_data,
                 )
 
+            if debug.flags.sql_output:
+                debug.header('SQL Output')
+                debug.dump_code(unit.query, lexer='sql')
+
             unit.stmt_name = compute_stmt_name(unit.query).encode("utf-8")
 
             tx_state.apply(unit)
             sql_units.append(unit)
 
         if not sql_units:
             # Cluvio will try to execute an empty query
-            sql_units.append(dbstate.SQLQueryUnit(query=""))
+            sql_units.append(dbstate.SQLQueryUnit(
+                orig_query='',
+                query='',
+                fe_settings=tx_state.current_fe_settings()
+            ))
 
         return sql_units
 

tests/test_sql_query.py

@@ -1043,3 +1043,6 @@ async def test_sql_query_prepare_error_01(self):
             position=str(len(query) - 3),
         ):
             await self.scon.execute(query)
+
+    async def test_sql_query_empty(self):
+        await self.scon.executemany('', args=[])