Search results
Results from the WOW.Com Content Network
In SQL the UNION clause combines the results of two SQL queries into a single table of all matching rows. The two queries must result in the same number of columns and compatible data types in order to unite. Any duplicate records are automatically removed unless UNION ALL is used.
A right join is employed over the Target (the INTO table) and the Source (the USING table / view / sub-query)--where Target is the left table and Source is the right one. The four possible combinations yield these rules:
INSERT INTO phone_book SELECT 'John Doe', '555-1212' UNION ALL SELECT 'Peter Doe', '555-2323'; ... and it can even query the same table into which the data is ...
The relational algebra uses set union, set difference, and Cartesian product from set theory, and adds additional constraints to these operators to create new ones.. For set union and set difference, the two relations involved must be union-compatible—that is, the two relations must have the same set of attributes.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
So if two tables are T1 and T2, SELECT * FROM T1, T2 will result in every combination of T1 rows with every T2 rows. E.g., if T1 has 3 rows and T2 has 5 rows, then 15 rows will result. Although not in standard, most DBMS allows using a select clause without a table by pretending that an imaginary table with one row is used.
Political analysts have wondered whether Democrats can turn this wave of progressive enthusiasm into concrete electoral gains in the 2018 midterms. One way to test that: special elections to fill empty state legislature and congressional seats.
Rhubarb is a vegetable high in fiber. "[Rhubarb is] rich in fiber, so it really helps with digestion. [It] has a pretty good source of fiber per serving," Wright told Fox News Digital.