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db_table.md

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Relation/Table

This is a general structure and naming conventions of a relational database relation/table.

Structure of a relation/relvar/table

Mixed naming conventions:

  • Tuple/record (rel. db.) = row (SQL) = observation (R/tidyverse).
  • Attribute/field (rel. db.) = column (SQL) = variable (R/tidyverse).
  • Relation (rel.db) = table (SQL).

Table:

  • Table is a set of records (in rows).
  • Rows and columns have no particular order (there are no row numbers).
  • Each column has a name unique within the table.
  • Each column keeps data from one domain (of one elementary type; e.g. integers).
  • Each row is different (related to the concept of key).
  • Each table has a name (unique within the database).