A link-relative ratio is a percentage got by comparing the data of current period and that of the previous period. Usually the interval between the two periods is a month (sometimes an hour, a day, a week and a quarter). The link-relative ratio of April is computed by dividing, for example, its sales amount by that of ...
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If k (a single field or a combination of fields) is table M’s primary key, and k, at the same time, exists in table B, then k is regarded as B’s foreign key. The foreign key defines a relationship between two tables and is one of the most important concepts for structured data computing. Through object references, esPr...
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