Support for 'distinct' and 'null' queries

[datasette-pytables.git] / datasette_pytables / __init__.py

diff --git a/datasette_pytables/__init__.py b/datasette_pytables/__init__.py
index e8d0a6ccb4519f72d2e0680e0c3b4b8f44dc2574..a1f11d91e3fb2e8b142068703fd4a8181e49ac33 100644 (file)
--- a/datasette_pytables/__init__.py
+++ b/datasette_pytables/__init__.py
@@ -37,7 +37,19 @@ def _parse_sql(sql, params):
     for param in params:
         sql = sql.replace(":" + param, param)
 
-    parsed = parse(sql)
+    try:
+        parsed = parse(sql)
+    except:
+        # Propably it's a PyTables expression
+        for token in ['group by', 'order by', 'limit']:
+            res = re.search('(?i)where (.*)' + token, sql)
+            if res:
+                modified_sql = re.sub('(?i)where (.*)(' + token + ')', '\g<2>', sql)
+                parsed = parse(modified_sql)
+                parsed['where'] = res.group(1)
+                break
+
+    # Always a list of fields
     if type(parsed['select']) is not list:
         parsed['select'] = [parsed['select']]
 
@@ -95,8 +107,12 @@ class Connection:
             operator = list(where)[0]
 
             if operator in ['and', 'or']:
-                subexpr = ["({})".format(_translate_where(q)) for q in where[operator]]
+                subexpr = [_translate_where(e) for e in where[operator]]
+                subexpr = filter(lambda e: e, subexpr)
+                subexpr = ["({})".format(e) for e in subexpr]
                 expr = " {} ".format(_operators[operator]).join(subexpr)
+            elif operator == 'exists':
+                pass
             elif where == {'eq': ['rowid', 'p0']}:
                 nonlocal start, end
                 start = int(params['p0'])
@@ -113,11 +129,10 @@ class Connection:
             return expr
 
         if 'where' in parsed_sql:
-            try:
+            if type(parsed_sql['where']) is dict:
                 query = _translate_where(parsed_sql['where'])
-            except:
-                # Probably it's a PyTables query
-                query = str(parsed_sql['where'])[6:]    # without where keyword
+            else:
+                query = parsed_sql['where']
 
         # Limit number of rows
         if 'limit' in parsed_sql:
@@ -139,16 +154,19 @@ class Connection:
             for table_row in table_rows:
                 row = Row()
                 for field in fields:
-                    if field['value'] == 'rowid':
+                    field_name = field['value']
+                    if type(field_name) is dict and 'distinct' in field_name:
+                        field_name = field_name['distinct']
+                    if field_name == 'rowid':
                         row['rowid'] = int(table_row.nrow)
-                    elif field['value'] == '*':
+                    elif field_name == '*':
                         for col in table.colnames:
                             value = table_row[col]
                             if type(value) is bytes:
                                 value = value.decode('utf-8')
                             row[col] = value
                     else:
-                        row[field['value']] = table_row[field['value']]
+                        row[field_name] = table_row[field_name]
                 rows.append(row)
 
         # Prepare query description