UNION
or UNION ALL
strategies.union
methods take either a Query Builder instance or a closure which you use to define a new QueryBuilder instance.union
methods are invoked, but the union
statements can be in any order in your API call stack. This means you can safely declare your union
method calls before the select
, from
and orderBy
calls on the source Query Builder instance.union()
— This method builds a SQL statement using the UNION
clause which combines two SQL queries into a single result set containing all the matching rows. The two queries must have the same defined columns and compatible data types or the SQL engine will generate an error. The union
clause only returns unique rows.unionAll()
— This builds a SQL statement using the UNION ALL
clause. This is the same as union
but includes duplicate rows. union
statement cannot contain a defined order. Any use of the orderBy()
method on the unioned QueryBuilder instances will result in an OrderByNotAllowed
exception. To order the results, add an orderBy()
call to the parent source Query Builder instance.true
false
false
unionAll
where possible.true
unionAll
statements will append it to the query.