Description:
Generate a cursor from a sequence.
Syntax:
A.cursor(k:n)
Note:
The function generates a cursor based on sequence A, divides the cursor data into n segments, and retrieves the kth segment.
Parameter:
|
A |
A sequence |
|
k |
Segment number |
|
n |
The number of data segments; retrieve all data out when both k and n are omitted |
Option:
|
@p |
Assume data is ordered by the first field and the division won’t put records having same first field to different segments |
Return value:
Cursor
Example:
|
|
A |
|
|
1 |
=demo.query("select * from SCORES") |
Return a sequence. |
|
2 |
=A1.cursor(1:3) |
Generate a cursor using A1’s sequence, divide the cursor into three segments, and retrieve the 1st segment to return. |
|
3 |
=A1.cursor() |
Generate a cursor using A1’s sequence; return all data of the cursor when parameters are absent. |
|
4 |
=demo.query("select CLASS,STUDENTID,SUBJECT,SCORE from SCORES").sort(CLASS) |
Return a sequence ordered by the 1st field. |
|
5 |
=A4.cursor@p(1:3) |
With @p option, put records having same Class value in one segment, during which records are not allocated strictly according to parameters k and n. |