A.field(F)

Read(726) Label: get field value, sequence,

Description:

Get values of a specified field of a sequence.

Syntax:

A.field(F)

Note:

The function loops through parameter A to get the value of the Fth field from each record, or the value of every string parameter F, and returns a sequence consisting of these values. Count backward if F<0. Return null if F exceeds the boundary number of the fields or it does not exist.

Parameter:

A

A sequence

F

The ordinal number of a field, or the string parameter in which a variable can be used to reference the field name

Option:

@r

When the return value is a record or record sequence, loop its members iteratively to get desired values

Return value:

A sequence

Example:

 

A

 

1

=demo.query("select * from EMPLOYEE")

 

2

=A1.field(2)

Return a sequence composed of values of the second field.

3

=A1.field(-2)

Return a sequence comprising values of the second-to-last field.

4

=A1.field("NAME")

Return a sequence composed of values of NAME field.

5

>arg1="NAME"

 

6

=A1.field(arg1)

Same as A4.

7

=demo.query("select * from EMPLOYEE where EID < 20")

 

8

=A7.group(STATE;~.avg(SALARY):avg,~:group)

9

=A8.field@r(3)

After A8’s 3rd column is returned, go on to return the 3rd column of the return value.

 

Related function:

r.field(F)

r.field(F,x)

A.field(F,x)