Parameters are used for creating Parameterized Commands. These are the commands that, after they have been initially defined and stored, use parameters to change some detail in the text of the command before it is executed.

Many providers supports the parameterized commands. These are commands in which the desired action is defined once, but variables (or parameters) are used to alter some details of the commands.

For example, an SQL SELECT statement or other SQL statement could use a parameter to define the matching criteria of a WHERE clause, and another to define the column name for a SORT BY clause.

There are four types of parameters: input parameter, output parameter, input/output parameter and return parameter.

With the , methods, properties and collections of a Parameter object, we can do the following:

Set or return the name of the parameter with the Name property.

Set or return the value of the parameter with the Value property. Value is the default property of the Parameter object.

Set or return parameter characteristics with the Direction, Attributes,Precision, NumericScale, Size, and Type properties.

Pass long binary or character data to the parameter object with the AppendChunk method.

Access provider-specific attributes by using the Properties collection.