When you create the DELETE statement, you can optionally define a condition that specifies which rows of the database table to delete. Any row that is found in the specified database table that matches the condition is deleted.
If you do not specify a condition, all rows of the target database table are deleted. Use the Design pane in the SQL Query Builder to specify the condition for deleting rows from the database table.
See your database vendor documentation for information on the syntax of DELETE statements. Different database vendors use different syntax.