Oracle Collection Operations

The set operation does not apply to lob,varray and escape table columns union, intersect, minus operators do not apply to long if the selection list contains an expression or function, you must define the column alias 1, Uinon: No weight union, for the expression or function. Sorted in ascending order of the first column 2, Uinon all: There is a heavy set, do not sort the result set 3, Intersect: intersection, the result of the first column in ascending order 4, minus: Difference set, the results of the first column in ascending order 5, you can use ORDER by, Must be placed after the last select, when the column name is the same, can be directly sorted by column name, if the difference can be sorted by location, you can also use aliases to make the same.

Oracle Collection Operations