Description:
Attach the record filtering action to a cursor and return the original cursor.
Syntax:
cs.select(x)
Note:
The function attaches a computation to cursor cs, which will calculate expression x against each of the records in cursor cs and get records that make value of x true, and return the original cursor cs.
When parameter x is omitted, get all records of cursor cs. The function supports multicursors.
This is a delayed function.
Parameter:
cs |
A cursor |
x |
A Boolean value |
Return value:
Cursor
Example:
|
A |
|
1 |
=demo.cursor("select * from SCORES") |
Return a cursor:
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2 |
=A1.select(STUDENTID>10) |
Attach a computation to cursor A1, which will select records where STUDENTID is greater than 10 from the cursor, and return cursor A1:
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3 |
=A1.fetch() |
Fetch data from cursor A1 where A2’s computation is executed (it would be better that data is fetched in batches when a large amount of data is involved):
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