Working With Other Database Types

Serenity has a dialect system for working with database types other than Sql Server.

If you need to support multiple database types, just by changing connection strings in web.config, you should be careful about not using database specific functions in expressions and avoid using reserved words.

Warning About CONCAT and Other Similar Expressions In Rows

Serene has to support a variety of database engines, including MySQL, Postgress etc. These databases don’t have a string plus (+) operator like MsSqlServer. Thus, in Northwind, CONCAT function is used in place of ‘+’ operator:

  1. [Expression("CONCAT(T0.[FirstName], CONCAT(' ', T0.[LastName]))")]
  2. public String FullName
  3. {
  4. get { return Fields.FullName[this]; }
  5. set { Fields.FullName[this] = value; }
  6. }

CONCAT is available after Sql Server 2012. So if you are going to use an older version of SQL server, e.g. 2005 or 2008, replace these expressions with such:

  1. [Expression("T0.[FirstName] + ' ' + T0.[LastName]")]
  2. public String FullName
  3. {
  4. get { return Fields.FullName[this]; }
  5. set { Fields.FullName[this] = value; }
  6. }