Sql. SQL SELECT. SQL Topics. SQL Tutorial - Union. SQL UNION combines two separate SQL queries into one result set.
A JOIN statement adds additional table columns to a result set (horizontally), UNION combines row results from one table with rows of another table (vertically). In order to perform a UNION the columns of table 1 must match those of table 2. This rule ensures that the result set is consistent as rows are fetched by SQL. MS Access [English]
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