Okuzeka
Data Science & Analytics vocabulary · SQL and Querying

Join

Meaning in data science & analytics, with examples

/dʒɔɪn/nounCore term

In data science & analytics, join means: An operation that combines rows from two or more tables using a shared column, such as a customer ID; as a verb, to combine tables in this way.

In Turkish: birleştirme, join, tabloları birleştirmek

How it is used

You write, do or fix a join, and you join one table to another 'on' a key. The main types are inner, left, right and full outer joins. A wrong join can silently duplicate or drop rows.

Example sentences

  1. I used a left join so that customers without orders still appear in the result.

  2. Join the orders table to the customers table on customer_id.

Common collocations

  • left join
  • inner join
  • join on a key
  • join two tables
  • SQLShort for Structured Query Language: the standard language for reading, filtering, combining and changing data stored in relational databases and data warehouses.
  • primary keyA column, or a set of columns, whose value is unique for every row in a table and is used to identify each row, such as an order ID.
  • duplicateA record that appears more than once in a dataset, for example the same customer or order stored twice, which can make counts and totals too high.
  • queryA request for specific data from a database, usually written in SQL; as a verb, to ask a database or dataset for that data.

This word in other fields

The same English word can have a different meaning in another field:

More terms: SQL and Querying

Practise with graded reading

Reading at the right level is the fastest way to make new words stick. Pick free English books by level: