Getting value from a second table based on 2 variable values

Question

I need to add a column in my sales table by matching 2 values with another table:

Example:

Table1 I need to add a column on this table

       PRODUCT       STORE    SALES
        A              Z        2
        A              X        4      
        B              X        4

Table2

       PRODUCT       STORE     TERMS
        A              Z        0
        A              X        1    
        B              X        3

I know how to match 1 value from each table with the match function:

Table1$Terms=Table2$Terms[match(Table1$Product,Table2$Product)]

However, I need to match both the Product code and the Store code

Needed result:

       PRODUCT       STORE    SALES    TERMS
        A              Z        2       0
        A              X        4       1 
        B              X        4       3

Checkout the [tag:r-faq] or search `[r] join`... everything about meging, joining, matching, etc... you'll likely ever need. — Thell, May 01 '14 at 00:13

score 2 · Accepted Answer · answered Apr 30 '14 at 20:52

2

Table1 <-  merge(Table1, Table2, by = c("PRODUCT", "STORE"), all.x = T)

##  PRODUCT STORE SALES TERMS
## 1       A     X     4     1
## 2       A     Z     2     0
## 3       B     X     4     3

answered Apr 30 '14 at 20:52

David Arenburg

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Getting value from a second table based on 2 variable values

1 Answers1