r .modify( x i : F i , … )

Read(188) Label: modify, field value,

Description:

Modify the field values of a record.

Syntax:

r.modify(xi:Fi,)

Note:

The function modifies the field values in record r, the status of r will be changed to 1(modify) after being modified. Automatically update the index, if any, and check distinctness.

Parameters:

r

The record to be modified

xi

Modification expression

Fi

Name of the field to be modified. The ith field in r will be modified if Fi isn’t supplied.

r'

The new record that will replace record r

Options:

@r(r')

Replace record r with record r' according to the former’s order

@f(r')

Modify a certain field value of record r with record r'

Return value:

The modified record r

Example:

 

A

 

1

=[[1,"Lucy",29]].new(~(1):ID,~(2):Name,~(3):Age)

2

=A1(1).modify(2,"Petter")

Modify the first and the second field

3

=A2.modify(30:Age)

Modify Age field

4

=A3.modify(3,33:Age)

Modify the first field and Age field

5

=[[4,"Lily",23]].new(~(1):SID,~(2):SName,~(3):SAge)

6

=A4.modify@r(A5(1))

 Fill members of A5(1) in A4 according to A4’s order

7

=A6.modify@f(([["ella"]].new(~(1):Name))(1))

 Modify only the value of Name field in A6

Related functions:

T.modify()

T.insert()

T.delete()