如何处理数据帧中的所有列并生成新列

Question

这是一个示例

我有一个数据帧

+---+---------+----+------------+-----+
| id|     name| age|   describle|value|
+---+---------+----+------------+-----+
|  0|hansongbo|null| he is great|   11|
|  1|   marong|  23|        null| null|
|  2|hansongbo|  34|        null| null|
|  3|   marong|  34|she love han|   12|
+---+---------+----+------------+-----+

现在我要计算所有字符串列的长度，结果是

 +---+---------+----+------------+-----+------+
| id|     name| age|   describle|value|length|
+---+---------+----+------------+-----+------+
|  0|hansongbo|null| he is great|   11|   20 |
|  1|   marong|  23|        null| null|   6  |
|  2|hansongbo|  34|        null| null|   9  |
|  3|   marong|  34|she love han|   12|   18 |
+---+---------+----+------------+-----+------+

我怎么能做到，希望你的帮助，谢谢！

Answer 1

让我们将数据帧命名为 A。

A.registerTempTable("tableA")
b = sqlContext.sql("select `id`,`name`,age,describle,value,length(`name`)+length(`describle`) as `length` from tableA")