The difference with just tables A flat table is a classic table a la SQL table in first normal form NF. Oneline header atomic data types. Overall beauty. When you are given such a table you can immeiately begin an interesting and useful stage of analysis. A table in general is everything that a person considers to be a table. Tables can be matrix double matrix with multiline headers nonatomic data types in the body etc. If you are given such a table.
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You will spend from minutes to several days translating it into a clear flat form. Sometimes this translation is not possible at all due to architectural errors or the quality of the source data. For clarity two photos This is NOT a flat table But this is a flat table Greece WhatsApp Number Data To convert the above table into a flat form more than one line of code was require. The translation code can here . Flat Table Architecture Lets introduce some basic terms. Candidate keys are sets of columns that ensure the uniqueness of each row in the table. More of a technical concept. The full set of potential keys is not of interest. The primary key of a table is what a flat table is all about.
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Each line contains one object. Each line tells something about this object. The primary key ensures that each row is unique. Those. A primary key is one of the candidate keys. Unfortunately not everyone who designs tables thinks about the primary key. And without this Greece Phone Number List you cant go anywhere. Functional dependencies . Let me give you an example. There is a directory of positions and there is a directory of employees. Lets assume that each employee has strictly one position. Thus the employee functionally defines the position. The reverse is usually not true.
