[#1871] Remove EXPLAIN bits from error messages

As we are running the EXPLAIN command to look for table names before the
actual command, if there is a syntax error, table does not exist, etc,
the error messages will include the EXPLAIN statement, not the one provided.

We remove the EXPLAIN bit from the statement before raising the
exception to avoid confusion.

ckanext/datastore/db.py

@@ -1183,12 +1183,17 @@ def search_sql(context, data_dict):
             raise toolkit.NotAuthorized({
                 'permissions': ['Not authorized to read resource.']
             })
+
+        def _remove_explain(msg):
+            return (msg.replace('EXPLAIN (FORMAT JSON) ', '')
+                       .replace('EXPLAIN ', ''))
+
         raise ValidationError({
-            'query': [str(e)],
+            'query': [_remove_explain(str(e))],
             'info': {
-                'statement': [e.statement],
+                'statement': [_remove_explain(e.statement)],
                 'params': [e.params],
-                'orig': [str(e.orig)]
+                'orig': [_remove_explain(str(e.orig))]
             }
         })
     except DBAPIError, e: