Specifies whether an application expects to receive a live result set when the query executes.
Syntax:
property RequestLive: Boolean;
Description:
Set RequestLive to specify whether or not the query should attempt to return a live result set to the application. RequestLive is False by default, meaning that a query always returns a read-only result set.
Set RequestLive to True to request a live result set. Setting RequestLive to True does not guarantee that a live result set is returned. MySQL returns a live result set only if the SELECT syntax of the query conforms to the syntax requirements for a live result set.
If RequestLive is True, but the syntax does not conform to the requirements, MySQL returns an error code for remote servers.
TMySQLQuery can't be "live" if meets one (or more) of following conditions:
▪SQL query contains more than one tables in "from" section
▪SQL query has JOINs
▪SQL query doesn't use tables at all:
SELECT VERSION
▪SQL query has some calculations or function calls in fields definitions:
SELECT field_name + 1 FROM table_name
▪SQL query doesn't contain at least one unique indexed field.
After activation of the TMySQLQuery you should inspect the CanModify property to determine if the request for a live resultset succeeded.
All multi-table queries return read-only result sets.
Your query will not be updatable if it is multi-resultset query. This means that you will not able to edit dataset if AvailableResultsetCount property is not equal to 1.
See also: TMySQLDataset.CanModify and AvailableResultsetCount properties