DBcancel

Synopsis

DBcancel cancels the currently executing query.

Input Ports

dbvisual_connect_descriptor ptr to a structure

process_cancel integer

Parameters

dbvisual_descriptor ptr to a structure

message string

connect_information DBconnectInformation group

return_code int

Output Ports

None

Description

DBcancel cancels the currently executing query. Canceling a query may be necessary for reasons such as the following:

The query is returning too many rows (it was not selective enough).

The query is returning the wrong data (it was stated incorrectly).

Input

dbvisual_connect_descriptor

A pointer to the connection descriptor of the session in which DBquery is to execute. This is the output of the DBconnect module that initiated the session.

CAUTION: Do not modify this value. A fatal error will result.

process_cancel

A trigger that initiates execution of the cancellation of a query. When this value changes to a value greater than 0, the cancel is executed.

Parameters

dbvisual_descriptor

For internal use only.

CAUTION: Do not modify this value. A fatal error will result.

message

A message that describes the status of the call to DBcancel.

connect_information

Information about the current connection:

the database driver

the server host

the server name

the database name

the user ID

the connect string

the status of the connection: connected (1) or disconnected (0)

This parameter is of type DBconnectInformation. For more information, see DBconnectInformation .

return_code

The status code associated with the message returned in the message parameter. A value of 0 indicates success; a nonzero value indicates failure. For a list of possible values, see The Toolkits Book .

Output Port

none.

Example

Not available.

File

v/db.v

See also related modules