using R how to read a one column alone from a database table from MySQL

i have a created a database table in MYSQL consisting of 11 columns.
throught RMYSQL i managed to read the entire table in R. but i have few
qureries which i need solutions...here they are:

1. Using R how to read a one column alone from a database table from MYSQL.
2. Using R how to print on screen those column value.
3. Using R how to print one particular row (in this case row is X)value
alone.
4. Using R how to read all the column (11) and print (X) value alone on
screen.
5. Using R with logic print those (X) value which is/between say 20 to 30
degrees.