# 7.30. ODPI-C Structure dpiSubscrMessageQuery

This structure is used for passing information on query change notification events and is part of the dpiSubscrMessage structure.

uint64_t dpiSubscrMessageQuery.id

  Specifies the id of the query that was registered as part of the subscription that generated this notification.

dpiOpCode dpiSubscrMessageQuery.operation

  Specifies the operations that took place on the registered query. It will be one or more of the values from the enumeration dpiOpCode, OR’ed together.

dpiSubscrMessageTable *dpiSubscrMessageQuery.tables

  Specifies a pointer to an array of dpiSubscrMessageTable structures representing the list of tables that were modified by the event which generated this notification.

uint32_t dpiSubscrMessageQuery.numTables

  Specifies the number of structures available in the `dpiSubscrMessageQuery.tables` member.