| 4.14.5 Base columns and generated columns |
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| A column of a base table is either a base column or a generated column. A base column is one that is not a generated column. |
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| A generated column is one whose values are determined by evaluation of a generation expression, a <value expression> whose declared type is by implication that of the column. |
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| A generation expression can reference base columns of the base table to which it belongs but cannot otherwise access SQLdata. Thus, the value of the field corresponding to a generated column in row R is determined by the values of zero or more other fields of R. |
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