gather
Converts several columns into two columns key
and value
. key
column will contain names of original columns, value
column will contain values from original columns.
This operation is reverse to pivot
See column selectors
Configuration options:
explodeLists
— gathered values of typeList
will be exploded into their elements, sowhere
,cast
,notNull
andmapValues
will be applied to list elements instead of lists themselvescast
— inform compiler about the expected type of gathered elements. This type will be passed towhere
andmapKeys
lambdasnotNull
— skip gatherednull
valueswhere
— filter gathered valuesmapKeys
— transform gathered column names (keys)mapValues
— transform gathered column values
Storage options:
into(keyColumn, valueColumn)
— store gathered key-value pairs in two new columns with nameskeyColumn
andvalueColumn
keysInto(keyColumn)
— store only gathered keys (column names) in a new columnkeyColumn
valuesInto(valueColumn)
— store only gathered values in a new columnvalueColumn