Use SQLConnection to specify an SQL connection object that connects the dataset to a database server.  

At design-time, select from the list of available TSQLConnection components in the Object Inspector. At runtime, set SQLConnection to reference an existing TSQLConnection object. 

SQLConnection should be the first property you set on the dataset. Only after the SQLConnection property is set can you use the Command Text editor to specify a query for the CommandText property or populate the dataset with data by setting Active to true. Similarly, SQLConnection must be set before the dataset can initialize the Params property when you set CommandText. 

Active 

CommandText 

Params 

Using Query-type Datasets 

Using Stored Procedure-type Datasets 

Using Table Type Datasets 

Connecting Directly to a Database Server 

Connecting to the Database Server