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The following page has been changed by RaghothamMurthy: http://wiki.apache.org/hadoop/Hive/LanguageManual/SubQueries New page: Syntax: {{{ SELECT ... FROM (subquery) name ... }}} Hive supports subqueries only in the FROM clause. The subquery has to be given a name because every table in a FROM clause must have a name. Columns in the subquery select list must have unique names. The columns in the subquery select list are available in the outer query just like columns of a table. The subquery can also be a query expression with UNION. Hive supports arbitrary levels of sub-queries. Example with simple subquery: {{{ SELECT col FROM ( SELECT a+b AS col FROM t1 ) t2 }}} Example with subquery containing a UNION ALL: {{{ SELECT t3.col FROM ( SELECT a+b AS col FROM t1 UNION ALL SELECT c+d AS col FROM t2 ) t3 }}}
