esProc Exports Data by Groups

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Problem source:http://bbs.csdn.net/topics/390500337 .

A selection from the original table (TB1):

esProc_sql_group_output_1

Note: The table has a great amount of data volume with 4 million rows of data.

You need to export data into several TXTfiles according to different values in PROGROUP column. Based on the above data, the expected result is as follows:

DG.txt

MONTH  ID   COMPANY    DEPARTMENT     JOINTIME     PROGROUP

201305    1009       1     A     A1   201108    DG

201305    1027       2     A     A3   201007    DG 

PG.txt

MONTH  ID   COMPANY    DEPARTMENT     JOINTIME     PROGROUP

201305    1009       1     B     B1   201207    PG 

SEG.txt

MONTH  ID   COMPANY    DEPARTMENT     JOINTIME     PROGROUP

201305    1009       1     D     D1   201109    SEG 

SG.txt

MONTH  ID   COMPANY    DEPARTMENT     JOINTIME     PROGROUP

201305    1009       1     C     C1   201301    SG

201305    1013       2     C     C2   201302    SG 

You can not store the grouped set in SQL (aggregation is required after grouping), which makes the coding really complicated. Besides, it is annoying to export the big data involved in the problem to TXT files in batches using cursors. esProc can handle the operation elegantly with its group cursor through a three-line script:

  A B
1 =db.cursor(“SELECT * FROM TB1 ORDER BY PROGROUP ASC”)
2 for A1;PROGROUP >file(“E:\\”+A2.PROGROUP+”.txt”).export@t(A2)

A1: Use the SQL statement to create and return a database cursor sorted by PROGROUP.

A2-B2: Group data by PROGROUP. Run a loop to retrieve a group of records each time and then export them in B2 to the corresponding TXT file named after a type of value in PROGROUP field. 

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