New design for NULL semantics

Now, instead of being specified as part of the SQL type with the type
pragma, there are separate null and not_null pragmas. The not_null
pragma was used to control NULL-ness of object pointers. Now the two
pragmas are used consistently for object pointers and simple values
(and in the future will work for composite values and containers).

1 files changed, 17 insertions, 1 deletions

diff --git a/odb/relational/mysql/schema.cxx b/odb/relational/mysql/schema.cxx
index 0b44c53..3848c75 100644
--- a/odb/relational/mysql/schema.cxx
+++ b/odb/relational/mysql/schema.cxx
@@ -37,11 +37,27 @@ namespace relational
         }
       };
 
-      struct object_columns: relational::object_columns
+      struct object_columns: relational::object_columns, context
       {
         object_columns (base const& x): base (x) {}
 
         virtual void
+        null (semantics::data_member& m)
+        {
+          if (!context::null (m, prefix_))
+            os << " NOT NULL";
+          else
+          {
+            // MySQL TIMESTAMP is by default NOT NULL. If we want it
+            // to contain NULL values, we need to explicitly declare
+            // the column as NULL.
+            //
+            if (column_sql_type (m, prefix_).type == sql_type::TIMESTAMP)
+              os << " NULL";
+          }
+        }
+
+        virtual void
         constraints (semantics::data_member& m)
         {
           base::constraints (m);