DELETE DATABASE is used with the DELETETABLES option to remove the database and itsfriendstable from disk. 复制 CLOSE ALL CREATE DATABASE people CREATE TABLE friends (FirstName C(20), LastName C(20)) CLEAR DISPLAY TABLES && Displays tables in the database DISPLAY DATABASES && Displays table...
DROP DATABASEdeletes all user data and log files, as well as any backup and restore history for the database. If the log files are needed for a rollforward recovery after a restore operation, or the backup history required to restore the database, these files should be saved before issuin...
Without a RETURNING clause the DELETE returns the number of rows deleted. Otherwise, for each deleted row the expressions following the RETURNING clause are computed the same way as in the SELECT clause and the result is returned to the application. Example 1: Delete data from a table with ...
CLOSE DATABASES OPEN DATABASE (HOME(2) + 'Data\testdata') USE customer && Opens Customer table DELETE FOR country = 'USA' && Mark for deletion CLEAR LIST FIELDS company, country FOR DELETED( ) && List marked records RECALL ALL && Unmark all records marked for deletion ...
For example, to drop the database called my_db, the MySQL command would be: DROPDATABASEmy_db; This command removes the database and also removes the directory and files on the database server for the database. Just like the other databases here, there is no MySQL “delete database” ...
DELETE Command DELETE CONNECTION Command DELETE DATABASE Command DELETE FILE Command DELETE TAG Command DELETE TRIGGER Command DELETE VIEW Command DIMENSION Command DIR or DIRECTORY Command DISPLAY Command DISPLAY CONNECTIONS Command DISPLAY DATABASE Command DISPLAY DLLS Command DISPLAY FILES Command DISPLAY ...
For example, run an audit if you open an LSM door and manually remove cartridges instead of ejecting them through the CAP. The audit deletes information for the removed cartridges from the database. View the contents of cells specified by the audit (you must have a display monitor connected...
ExecuteNonQueryExecutes commands such as SQL INSERT, DELETE, UPDATE, and SET statements. ExecuteScalarRetrieves a single value, for example, an aggregate value, from a database. You can reset theCommandTextproperty and reuse theOdbcCommandobject. However, you must close theOdbcDataReaderbefore you ...
Insert, update, and delete data Return a single value Command-based database operations can run within a transaction, if needed. For a short tutorial demonstrating how and when to use theExecuteReader,ExecuteNonQuery, andExecuteScalarmethods, seeSection 6.1.2, “The MySqlCommand Object”. ...
If you move or rename the picture file, Access displays an error message when you open the database, and the command button displays its caption instead of the picture. Display both a picture and a caption on a command button You can display both a caption ...