The statement “in relational databases, each individual space within a row or column contains exactly one value” is basically true as a principle of the relational model, but with some important nuances in practice.

Quick Scoop

  • In a relational table, each cell (the intersection of a row and a column) is meant to hold one atomic value of that column’s data type, such as one number, one date, or one text string.
  • This idea is part of First Normal Form (1NF) : columns represent attributes, rows represent records, and each cell holds a single, indivisible value for that attribute.
  • Modern database systems stretch this a bit by allowing “complex” values like JSON, XML, or arrays in a single column, but logically those are still treated as one value from the database’s point of view.
  • A missing value is represented with NULL , which is a special marker meaning “no value”, not a second value in the same cell.

What a “Space” Really Is

When people say “individual space within a row or column,” they are talking about a cell :

  • A row is a record (for example, one customer or one order).
  • A column is an attribute (like Name, Email, or JoinDate), and every row must give one value for that attribute in its cell.

So a table with columns CustomerID, Name, and Email will have, for each row:

  • One CustomerID value in its cell.
  • One Name value in its cell.
  • One Email value in its cell.

The Role of “Atomic” Values

The relational model pushes the idea of atomic (indivisible) values per cell:

  • A column’s data type (like INT, VARCHAR, or DATE) controls what a single value looks like in that cell.
  • If you start packing multiple logical values into one cell (like a comma‑separated list of phone numbers), you make searching, indexing, and joining much harder and violate the spirit of 1NF.

That is why designers often create separate tables when something is “many” (for example, many phone numbers per person) instead of cramming them into one cell.

Modern Databases and “One Value”

Reality today is a bit more flexible, but the logical rule is the same:

  • Some systems let columns store JSON, XML, images, or documents in a single cell.
  • Even then, the cell still holds one value of its type (for example, “one JSON document”), even if that value is internally structured.

So the clean theoretical version of the statement is:

In a relational database table, each cell holds one atomic value of the column’s declared type for that row.

Very Short TL;DR

  • Yes: each cell in a relational table is supposed to contain one value (or NULL) for that column and row.
  • This is the basis of First Normal Form and is key to making data easy to query, index, and relate.

Information gathered from public forums or data available on the internet and portrayed here.