SQLDF merge in R:计算两个日期之间的NA值

install.packages("sqldf")

library(sqldf)

# 创建示例数据框
df1 <- data.frame(date = c("2022-01-01", "2022-01-02", "2022-01-03"),
                  value = c(1, NA, 3))

df2 <- data.frame(date = c("2022-01-01", "2022-01-03", "2022-01-04"),
                  value = c(10, 20, 30))

# 将日期列转换为日期类型
df1$date <- as.Date(df1$date)
df2$date <- as.Date(df2$date)

# 使用merge函数计算两个日期之间的NA值
result <- sqldf("SELECT df1.date, df1.value
                FROM df1
                LEFT JOIN df2 ON df1.date = df2.date
                WHERE df2.date IS NULL")

# 打印结果
print(result)