Merge dataset on corresponding column values in R -

this question has answer here:

• how join (merge) data frames (inner, outer, left, right)? 11 answers

dataset1

 ordernumbers   column1   column2   column3 1. 523542          x         x       x 2. 474822          x         x       x 3. 456453          x         x       x 4. 124132 5. 342142 6. 342122 7. 432522 8. 432134 9. 234234 

dataset2

transformantid   columna   columnb   columnc 1. 124132         x         x       x 2. 234234         x         x       x 3. 342142         x         x       x 4. 474822 5. 523542         y         w       z   6. 432522 7. 456453  

my goal merge these 2 dataframes. column "ordernumber" dataset1 matches vlaues values column "transformantid" dataset 2. include rows dataset2 in dataset1 transformantid value matches ordernumber value so:

ordernumbers   column1   column2   column3  columna   columnb   columnc 1. 523542          x         x       x        y         w         z 

and have done every row in first dataset. number of rows dataset1 exceed of dataset2.

merge( dataset1 , dataset2 , by.x = "ordernumbers" , by.y = "transformantid" )