outer join
Transcription
-
- US Pronunciation
- US IPA
-
-
- US Pronunciation
- US IPA
-
Definitions of outer join words
- noun Technical meaning of outer join (database) A less commonly used variant of the inner join relational database operation. An inner join selects rows from two tables such that the value in one column of the first table also appears in a certain column of the second table. For an outer join, the result also includes all rows from the first operand ("left outer join"), or the second operand ("right outer join"), or both ("full outer join"). A field in a result row will be null if the corresponding input table did not contain a matching row. For example, if we want to list all employees and their employee number, but not all employees have a number, then we could say (in SQL-92 syntax, as used by Microsoft SQL Server): SELECT employee.name, empnum.number FROM employee LEFT JOIN empnum ON employee.id = empnum.id or, in Sybase syntax: SELECT employee.name, empnum.number FROM employee, empnum WHERE employee.id *= empnum.id The "*" on the left means "left outer join". "*=*" would be a full outer join. In Oracle syntax: SELECT employee.name, empnum.number FROM employee, empnum WHERE employee.id = empnum.id (+) Note that the "(+)" on the right means "left outer join". These all mean that all rows from the left-hand "employee" table will appear in the result, even if there is no match for their ID in the empnum table. Where there is no empnum.id equal to a given employee.id, a result row is output anyway but with all result columns from the empnum table null (empnum.number in this case). 1
- noun outer join (databases) A set of records that combines every record from a set of tables. 0
Information block about the term
Parts of speech for Outer join
noun
adjective
verb
adverb
pronoun
preposition
conjunction
determiner
exclamation
See also
Matching words
- Words starting with o
- Words starting with ou
- Words starting with out
- Words starting with oute
- Words starting with outer
- Words starting with outerj
- Words starting with outerjo
- Words starting with outerjoi
- Words starting with outerjoin
Was this page helpful?
Thank you for your feedback! Tell your friends about this page
Tell us why?