Params is a TStrings object listing the connection parameters. Each entry in the string list has the form

Name=Value

where Name is the name of the parameter and Value is its value. If you are using named connection configurations (the ConnectionName property), the values for each parameter are loaded from the dbxconnections.ini file when you set ConnectName. 

At design time, you can set parameter values using the string list editor by double clicking on the Params property in the Object Inspector. Any new values you set override the values loaded when you set ConnectionName unless you load the connection configuration at runtime using LoadParamsFromIniFile or LoadParamsOnConnect. 

The particular parameters that appear depend on the database server. The Params property is initialized to include a string for each parameter when you set the DriverName property. One particular parameter, Database, is required for all servers. Its value depends on the server you are using. For example, with InterBase, Database is the name of the .gdb file, while with MySQL, it is the database name that was assigned by the CREATE DATABASE command. 

Other typical parameters include HostName (the machine name or IP address of where the server is located), and TransIsolation (the degree to which transactions are isolated from changes made by other users of the database). 

ConnectionName 

LoadParamsFromIniFile 

LoadParamsOnConnect 

DriverName 

LocaleCode 

Setting Up TSQLConnection