The NVL Function |
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The Null ValueAn empty or blank field is said to contain NULL. A NULL is defined as a value that is unavailable, unassigned, unknown, or inapplicable. A NULL is not the same as a zero or a space. Zero is a number, and a space is a character. The COMMISSION_PCT column in the EMPLOYEES table can contain NULLs. Columns of any data type can contain NULLs unless the column was defined as NOT NULL when the table was created. Also, primary key columns cannot have NULLs. NVL FunctionYou can use the NVL function to convert a NULL to another value. NVL ( expr1, expr2)
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