蜂巢/猪 - 列到行转换

Question

输入数据

**Col1| Col2 | Col3 | Col4**

 2  | 500 | 50 | 100

如何将列转换为hive或pig中的行？

预期输出：

**Column  | Value**

Col1  |   2

Col2  | 500

Col3  | 50

Col4  | 100

Answer 1

您正在寻找UNPIVOT。

SELECT 'Col1' as 'Column' ,Col1  AS Value FROM htable
UNION ALL
SELECT 'Col2' as 'Column' ,Col3  AS Value FROM htable
UNION ALL
SELECT 'Col3' as 'Column' ,Col3  AS Value FROM htable
UNION ALL
SELECT 'Col4' as 'Column' ,Col4  AS Value FROM htable

Answer 2

SELECT col1     ，COL2 FROM（     选择地图（＆＃39; Col1＆＃39;，Col1，＆＃39; Col2＆＃39;，Col2，＆＃39; Col3＆＃39;，Col3，＆＃39; Col4＆＃39;，Col1）AS tmp     来自mytable     ）mytab LATERAL VIEW EXPLODE（mytab.tmp）explode_tmp AS col1     ，COL2