the set-theoretic operation yielding all those elements that are contained in either of two operand sets, equivalent to the logical "or"
a set containing all and only the members of two or more given sets; "let C be the union of the sets A and B"
a specialized SQL operation that combines the results from two or more independent queries or tables into a single result
The union of two events is the event that at least one of the two events happens.
(set theory) The union of sets A and B is the set of all elements of A and all elements of B.
The BOOLEAN union of two sets of element (A OR B) is the set of elements present in A or in B or in both A and B.
The collection of all elements of two or more sets.
(RA,SQL) Operation as defined in set theory, returning the union of the tuples/rows of two relations/tables over the same scheme. setops.php
combines all rows from two or more tables
This consists of all of the items from two or more sets, similar to "AND" in a function. For example, the union of {1,2,3} and {3,4,5} is {1,2,3,4,5}....
Returns unique items of two sets. select sname, major from student where major = 'COSC' UNION SELECT sname, major from student where major = 'MATH'; Unique Constraints - (U) Similar to primary in that the value is unique in the table, but a field that is a unique constraint is not the primary key for the record. Can be NULL.
when two or more congregations are amalgamated into one
A union of two sets A and B (written A B) is the set consisting of all the elements that are in either or both of those two sets. For example if A={1, 2, 3} and B={3, 4, 5}, A B= {1, 2, 3, 4, 5}.
A data set consisting of the combination of that data from two or more sets of data. Typically, a union is the combined set of rows from two or more specified tables.
A set, every member of which is an element of one or another of two or more given sets. The combination of two spatial data sets where the result includes all of the features of the two inputs.
(n) The Boolean operation that combines the two specified solids. If the two solids intersect, the intersecting geometry is only represented once in the resulting solid.
topological overlay of two polygonal spatial data sets which preserves features that fall within the spatial extent of either input data set; that is, all features from both coverages are retained. See also intersect and identity.
In set theory and other branches of mathematics, the union of a collection of sets is the set that contains everything that belongs to any of the sets, but nothing else.
In computer science, a union is a data structure that stores one of several types of data at a single location. There are only two safe ways of accessing a union object. One is to always read the field of a union most recently assigned; tagged unions enforce this restriction.
