"[url]Transpose rows and columns Transpose is to realize the conversion between rows and columns, .."

pjf RaqForum 22 No.
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Transpose rows and columns of a CSV file

Transpose rows and columns

Transpose is to realize the conversion between rows and columns, that is, the values in the rows are used as column names.

Example: Sales table classified by channel, recorded by date. Part of the data is as follows:

YEAR,MONTH,ONLINE,STORE
2020,1,2440,3746.2
2020,2,1863.4,448.0
2020,3,1813.0,624.8
2020,4,670.8,2464.8
2020,5,3730.0,724.5
...

Expect to get the following format result:

CATEGORY,1,2,3,…
ONLINE,2440,1863.4,1813.0,…
STORE,3746.2,448.0,624.8,…

esProc SPL script:

	A
1	=T(“MonthSales.csv”).select(YEAR:2020)
2	=A1.pivot@r(YEAR,MONTH; CATEGORY, AMOUNT)
3	=A2.pivot(CATEGORY; MONTH, AMOUNT)

Use the function A.pivot@r()to convert rows and A.pivot() to convert rows to columns according to the logical sequence.

Aggregate and transpose

The actual application of PIVOT basically follows the grouping and aggregation operation, after processing each row of data in the transposed column into a unique value through grouping, and then expanding the value of each row as the column name.

CLASS,STUDENTID,SUBJECT,SCORE
1,1,English,84
1,1,Math,77
1,1,PE,69
1,2,English,81
1,2,Math,80
...,...,...,...

Expect to get the following format result:

CLASS,MAX_MATH,MAX_ENGLISH,MAX_PE
1,97,96,97
2,97,96,97
…,…,…,…

esProc SPL script:

	A
1	=T(“Scores.csv”)
2	=A1.groups(CLASS,SUBJECT; max(SCORE):MAX_SCORE)
3	=A2.pivot(CLASS; SUBJECT, MAX_SCORE; “Math”:“MAX_MATH”, “English”:“MAX_ENGLISH”, “PE”:“MAX_PE”)