Join (SQL)
An SQL join clause combines records from two or more tables in a database. It creates a set that can be saved as a table or used as is. A JOIN is a means for combining fields from two tables by using values common to each. ANSI standard SQL specifies four types of JOIN: INNER, OUTER, LEFT, and RIGHT. As a special case, a table (base table, view, or joined table) can JOIN to itself in a self-join.
A programmer writes a JOIN predicate to identify the records for joining. If the evaluated predicate is true, the combined record is then produced in the expected format, a record set or a temporary table.
Read more about Join (SQL): Sample Tables, Inner Join, Outer Joins, Merge Rows, Alternatives, Implementation
Famous quotes containing the word join:
“Each man, if he attempts to join himself to others, is on all sides cramped and diminished of his proportion; and the stricter the union, the smaller and the more pitiful he is. But leave him alone, to recognize in every hour and place the secret soul, he will go up and down doing the works of a true member, and, to the astonishment of all, the work will be done with concert, though no man spoke.”
—Ralph Waldo Emerson (1803–1882)