The Oracle DUAL table is a table created by Oracle and is used for selects statements that do not have a table name to go along with them.
For example, the DUAL table can be used to select pseudo columns, such as getting the currval or nextval from an Oracle sequence.
SELECT myseq.nextval FROM DUAL;
The DUAL table has one column, named “DUMMY,” which is a VARCHAR2 datatype of length 1. The value of the record is “X.”
All Oracle users have access to the DUAL table, although it is owned by “SYS.”
The DUAL table should not be updated, altered, or deleted.
Filed under: Database, Oracle, Programming, SQL, Software, Technology, pl/sql | Tagged: dual, Oracle, tables
