Here’s how to use delete() function.
Description:
Delete specified records from a table sequence.
Syntax:
|
T.delete(k) |
Delete the kth record. |
|
T.delete(p) |
Delete records whose sequence numbers exist in p. |
|
T.delete(A) |
Delete records that exist in sequence A. |
Note:
The function deletes the specified records from table sequence T. The deleted records will be always saved in the delete buffer.
Parameter:
|
T |
A table sequence. |
|
k |
A positive integer, which specifies the position of a record to be deleted. |
|
p |
An integer sequence with the length of n, which specifies the positions of the records to be deleted. |
|
A |
A sequence, which specifies the records to be deleted. |
Option:
|
@n |
Return the deleted record or a record sequence of the deleted records. |
Return value:
Table sequence
Example:
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|
A |
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|
1 |
=demo.query("select * from EMPLOYEE") |
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2 |
=A1.delete(1) |
Delete the first record. |
|
3 |
=A1.delete([2,4,6]) |
Delete the second, the fourth and the sixth records. |
|
4 |
=A1.select(EID>5) |
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5 |
=A1.delete(A4) |
Delete the records whose EID is more than 5. |
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6 |
=A1.delete@n(1) |
Return the deleted record. |
Note:
We use the store address, instead of the field names or field values, to judge whether the records specified by A exist in T. So to delete the specified records, we generally use the function T.delete(T.select(…)) to locate them.
Related function:
Description:
Delete specified members from a sequence.
Syntax:
|
A.delete(k) |
Delete the kth member. |
|
A.delete(p) |
Delete members whose sequence numbers exist in p; count backward when a member of sequence p is less than 0. |
Note:
The function deletes the kth member or the members whose sequence numbers exist in p from sequence A.
Parameter:
|
A |
A sequence. |
|
k |
A positive integer that indicates the position of a member to be deleted in the sequence. |
|
p |
An integer sequence with the length of n that specifies the positions of the members to be deleted. |
Option:
|
@n |
Return the deleted record or a record sequence of the deleted records. |
Return value:
Sequence
Example:
|
|
A |
|
|
1 |
=["a","c","d","e","f"] |
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|
2 |
=A1.delete([2,4,5]) |
[a,d] |
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3 |
=demo.query("select * from STUDENTS") |
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4 |
=A3.delete@n(2) |
Return the deleted record.
|
|
5 |
=["a","c","d","e","f"].delete([3,-5]) |
Count backward to get the value [c,e,f] since one member of the sequence parameter is less than 0. |
Related function: