3.7. TFDCommand component
The TFDCommand
component is used to execute SQL queries. It is not descended from TDataSet
so it is valid to use only for executing SQL queries that do not return datasets.
Property | Purpose |
---|---|
| Reference to the |
| The transaction within which the SQL command will be executed |
| Type of command. The types are described in the section below. |
| SQL query text |
3.7.1. Types of Command
Usually, the command type is determined automatically from the text of the SQL statement. The following values are available for the property TFDCommand.CommandKind
to cater for cases where the internal parser might be unable to make correct, unambiguous assumptions based on the statement text alone:
skUnknown
unknown. Tells the internal parser to determine the command type automatically from its analysis of the text of the command
skStartTransaction
a command for starting a transaction
skCommit
a command for ending and committing a transaction
skRollback
a command for ending and rolling back a transaction
skCreate
a CREATE …
command for creating a new metadata object
skAlter
an ALTER …
command for altering a metadata object
skDrop
a DROP …
command for deleting a metadata object
skSelect
a SELECT
command for retrieving data
skSelectForLock
a SELECT … WITH LOCK
command for locking the selected rows
skInsert
an INSERT …
command for inserting a new record
skUpdate
an UPDATE …
command for modifying records
skDelete
a DELETE …
command for deleting records
skMerge
a MERGE INTO …
command
skExecute
an EXECUTE PROCEDURE
or EXECUTE BLOCK
command
skStoredProc
a stored procedure call
skStoredProcNoCrs
a call to a stored procedure that does not return a cursor
skStoredProcWithCrs
a call to a stored procedure that returns a cursor