Ways of Opening Informix Databases
1. Opening through FireDAC interface. Select FireDAC interface, click Informix, then fill all needed database parameters.
2. Opening through ODBC DSN. Select ADO or BDE interface, then choose ODBC data source option and then select the needed ODBC DSN from the drop-down list. But first, you should create an ODBC DSN of the corresponding type using Windows administrative tools, and point it to the database.
3. Opening through BDE alias. Select BDE interface, then choose Alias option and then select the needed alias from the drop-down list. But first, you should create the alias of type INFORMIX using BDE Administrator tool or Tools | BDE | Aliases menu of Database Tour, and point it to the database.
4. Opening through connection string. Select ADO interface, then choose Connection string option and write a connection string. This way is very flexible and allows to specify many additional parameters in the connection string and override standard Database Tour connection behavior. It is recommended for advanced users. Here are basic connection strings (more examples and details can be found in the Internet):