RETRIEVE is to extract data from the connected database according to the syntax of the data window.

Usage: firstly, connect the data window with the database, and in the open event of the window or the constructor event of the data window, dw _1.settransobject (sqlca). After the connection is completed, you can write dw_ 1.retrieve ().

You can also query with parameters. You need to set parameters in the data window, and then dw_ 1.retrieve (parameter 1, parameter 2 ...).

The order and type of parameters must correspond to the data window.

The return value is the number of rows obtained by the query