First of all, key word = code word, so primary key = primary key = primary key, candidate key = candidate key = candidate key... The
primary key is to select a candidate key from multiple candidate keys
Exam preparation soft test: a clear summary of candidate codes, primary codes, full codes, foreign codes, primary attributes, primary keys, primary keywords, and non-primary attributes
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Origin blog.csdn.net/qq_45560230/article/details/132668408
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