column
A data item within a row, whose storage and semantics are defined by a data type. Each table and index is largely defined by the set of columns it contains.
Each column has a cardinality value. A column can be the primary key for its table, or part of the primary key. A column can be subject to a unique constraint, a NOT NULL constraint, or both. Values in different columns, even across different tables, can be linked by a foreign key relationship.
In discussions of MariaDB internal operations, sometimes field is used as a synonym, while row is the preferred term when discussing SQL.
See also cardinality.
See also foreign key.
See also index.
See also primary key.
See also row.
See also SQL.
See also table.
See also unique constraint.