Aetna
Adquirido por CVS Health
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A empresa Aetna agora é parte da empresa CVS Health. For up-to-date information, please see the CVS Caremark Corporation profile..
Pergunta de entrevista da empresa Aetna
Q: In SQL, what is the difference between a union, join and append?
Resposta da entrevista
Sigiloso
1 de nov. de 2017
A union creates a larger horizontal data set that may have no connection, a join relates two tables that are semantically connected by an index, an append simply adds the contents of one table to the end of another table.