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Answer Posted / dave
The dual table is a dummy table with one row and one column. Functions that do not require any table data can be evaluated by SELECTing from the dual table. For example,
SELECT SYSDATE FROM DUAL
returns the system time and date. The DUAL table is needed to get around the fact that the SELECT command in Oracle requires a FROM clause. For example, "SELECT SYSDATE" would fail because no tables were specified.
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