TIsahCDSQuery

Description

TIsahCDSQuery represents a dataset with a result set that is based on an SQL statement.

Details

Use TIsahCDSQuery to access one or more tables in a database using SQL statements.

Query components are useful because they can:

• access more than one table at a time (called a 'join' in SQL).
• automatically access a subset of rows and columns in its underlying table(s), instead of returning all rows and columns.

Use the TIsahCDSQuery object for browsing and manipulating sets of data. By using update objects, data can be manipulated.

The fields of a TIsahCDSQuery dataset are all Isah types (TIsahFloatField,TIsahBooleanField, TIsahDateTimeField, TIsahIntegerField, TIsahMemoField, TIsahSmallIntField, TIsahStringField). These field types have their own set of specific properties.

In general it is recommended to set the field properties instead of the properties exposed by the visual components.

TIsahCDSQuery Properties

Property Active: Boolean (R/W)

Specifies whether or not a dataset is open. Use Active to determine or set whether a dataset is populated with data. When Active is false, the dataset is closed; the dataset cannot read data and data-aware controls can not use it to fetch data. When Active is true, the dataset can be populated with data.

Property DatabaseName: String (R/W)

Specifies the name of the database associated with this dataset. Use DatabaseName to specify the name of the database to associate with this dataset component. DatabaseName should match the name of a database component used in the application.

Note: Attempting to set DatabaseName in case a database already associated with this component is open, will cause an exception.

Property Params: Params list (R)

Contains the parameters for a query's SQL statement. Access Params at runtime to view and set parameter names, values, and data types dynamically (at design time use the collection editor for the Params property to set parameter information). Params is a zero-based array of TParams parameter records. Index specifies the array element you want to access.

Property SQL: TStringList object (R)

Contains the text of the SQL statement you want to execute. Use SQL to provide the SQL statement that a query component executes when its ExecSQL or Open method is called. At design time the SQL property can be edited by calling the String List editor in the Object Inspector. The SQL property can contain only one complete SQL statement at a time.

Property UpdateObject: TIsahBaseCDSUpdateObject object (R)

Specifies the update object component used to update the result set.