internal override bool BuildWhere(ExtentStatement statement, string alias)
        {
            var schema      = statement.Mapping;
            var inStatement = statement.CreateChild(this.inExtent, this.association);

            inStatement.UseRole(this.association.RoleType);

            if ((this.association.IsMany && this.association.RoleType.IsMany) || !this.association.RelationType.ExistExclusiveClasses)
            {
                statement.Append(" (" + this.association.SingularFullName + "_A." + Mapping.ColumnNameForAssociation + " IS NOT NULL AND ");
                statement.Append(" " + this.association.SingularFullName + "_A." + Mapping.ColumnNameForAssociation + " IN (\n");
                this.inExtent.BuildSql(inStatement);
                statement.Append(" ))\n");
            }
            else
            {
                if (this.association.RoleType.IsMany)
                {
                    statement.Append(" (" + alias + "." + schema.ColumnNameByRelationType[this.association.RelationType] + " IS NOT NULL AND ");
                    statement.Append(" " + alias + "." + schema.ColumnNameByRelationType[this.association.RelationType] + " IN (\n");
                    this.inExtent.BuildSql(inStatement);
                    statement.Append(" ))\n");
                }
                else
                {
                    statement.Append(" (" + this.association.SingularFullName + "_A." + Mapping.ColumnNameForObject + " IS NOT NULL AND ");
                    statement.Append(" " + this.association.SingularFullName + "_A." + Mapping.ColumnNameForObject + " IN (\n");
                    this.inExtent.BuildSql(inStatement);
                    statement.Append(" ))\n");
                }
            }

            return(this.Include);
        }