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data_concept:primary_key [2023/02/19 19:21]
peter
data_concept:primary_key [2024/03/08 13:33] (current)
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 ===Definition=== ===Definition===
-A primary key is [[data_concept:data element|data element]] that uniquely identifies a [[data_concept:data record|data record]].+A primary key is one or more [[data_concept:data element|data element]] that uniquely identifies a [[data_concept:data record|data record]]. 
 + 
 +===Relation=== 
 +|Primary key| is child of |[[data_concept:data element|data element]]| 
 +|Primary key|identifies|[[data_concept:data record|data record]]| 
 +|Primary key|can be used as link to another [[data_concept/data_record|data record]] by a|[[data_concept/foreign_key|foreign key]]| 
 + 
 +{{tag>All}}
  
-===Note=== 
-A primary key can also consists of more than one [[data_concept:data element|data element]].  
data_concept/primary_key.1676834506.txt.gz · Last modified: 2024/03/08 13:33 (external edit)