Esempio n. 1
0
        public SqlQuery QueryVersions(DatasetInfo baseTable, DatasetInfo versionedTable, Expression expression)
        {
            var sql = new SqlBuilder(adapter);

            var v = new SchemaObject(versionedTable.Name, "v");

            var a = new SchemaObject(baseTable.Name, "a");

            sql.Append("SELECT ");

            sql.WriteColumns(versionedTable.Members, prefix: "v"); // mutable values, primary keys, ...

            sql.Append(", ");

            sql.WriteColumns(baseTable.Members.Where(m => !m.IsVersion && !m.IsKey && !m.IsMutable), prefix: "a"); // immutable values from base table

            sql.From(v); // SELECT from v

            var keyName = baseTable.PrimaryKey[0].Name;

            // join the base (immutable) values with the versioned values
            sql.InnerJoin(
                baseTable       : v,        // versioned values
                joinedTable     : a,        // base values
                baseColumn      : keyName, 
                joinedColumn    : keyName
            );

            sql.Where(Expand(expression, baseTable)); 

            return new SqlQuery(sql.ToString(), sql.Parameters);
        }