cs.join ()

Description:

A foreign-key-style join between a cluster cursor and a record sequence.

Syntax:

cs.join(C:.,T:K,x:F,…; …;…)

Note:

The function matches foreign key field C, of cluster cursor cs with the key of parameter T to find corresponding records in table T. Add an F field represented by x, which is T’s field expression, to cs and return the original cluster cursor. K can be omitted or represented by #. When omitted, K is T’s key; when written as #, K is represented by a sequence number. It supports the multicursor.

Options:

@c

With a distributed cluster table, the operation won’t involve a cross-node reference but it assumes that the referenced records are local

Parameters:

cs

A cursor/multicursor/cluster cursor

C

cs’s foreign key; separate multiple fields in a composite key with the colon

T

A cluster memory table

K

T’s key

x

T’s field expression

F

Name of T’s field expression

Return value:

The original cursor

Example:

 

A

 

1

[192.168.18.143:8281]

 

2

=file("emp_1.ctx":[2], A1)

 

3

=A2.open()

 

4

=A3.cursor()

A cluster cursor

5

[192.168.0.110:8281]

 

6

=file("PERFORMANCE.ctx":[1],A5)

 

7

=A6. open ()

 

8

=A7.cursor()

 

9

=A8.memory()

A cluster memory table

10

=A4.join(EID,A9:EMPLOYEEID, BONUS*12:total)

Match EID field of A4’s cluser cursor with the key field EMPLOYEEID of A9’s cluster memory table, make the value of calculating expression BONUS*12 over the memory table total field and join it up with the cluster cursor, and return the cluster cursor

11

=A10.fetch()

Fetch data from A10’s cursor