hemant kumar
What is the difference between UNION and UNION ALL in SQL?
1 Answer(s)      4 years and 5 months ago
Posted in : SQL

What is the difference between UNION and UNION ALL in SQL?

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November 19, 2010 at 5:44 PM


Hi,

UNION is an SQL keyword used to merge the results of two or more tables using a Select statement, containing the same fields, with removed duplicate values(selects distinct values). UNION ALL does the same, however it persists duplicate values i.e. UNION ALL selects all values.

Thanks,