错误找不到R程序中的所有函数

Question

这是程序但是当我运行它时说找不到函数dbSendQuery或dbCoonect或程序中的任何函数。我不确定是不是因为我没有安装正确的软件包

 install.packages("RMySQL")

library(RMySQL)






mydb <- dbConnect(MySQL(), dbname='W1547901_0', user='',password='',host='elephant.ecs.westminster.ac.uk')

dbSendQuery(mydb, "drop table if exists books")
# creating tables in bookstore:

dbSendQuery(mydb, "
            CREATE TABLE books (
            book_id INT,
            title VARCHAR(50),
            publisher VARCHAR(50));")



dbListTables(mydb)

dbSendQuery(mydb, "INSERT INTO books
            (book_id, title, publisher)
            VALUES(1, 'R and MySQL', 'Addison Wesley');")

try1 = fetch(dbSendQuery(mydb, "SELECT book_id, title, publisher
FROM books
                         WHERE book_id = 1 ;"))