基于不同的连接条件合并R中的数据帧？

# 创建两个数据帧
df1 <- data.frame(ID = c(1, 2, 3, 4),
                  Name = c("Alice", "Bob", "Charlie", "David"))

df2 <- data.frame(ID = c(1, 2, 3, 5),
                  Age = c(25, 30, 35, 40))

# 根据ID列进行内部连接
merged_df <- merge(df1, df2, by = "ID")
print(merged_df)

# 创建两个数据帧
df1 <- data.frame(ID = c(1, 2, 3, 4),
                  Name = c("Alice", "Bob", "Charlie", "David"))

df2 <- data.frame(ID = c(1, 2, 3, 5),
                  Age = c(25, 30, 35, 40))

# 根据ID列进行左连接
merged_df <- merge(df1, df2, by = "ID", all.x = TRUE)
print(merged_df)

# 创建两个数据帧
df1 <- data.frame(ID = c(1, 2, 3, 4),
                  Name = c("Alice", "Bob", "Charlie", "David"))

df2 <- data.frame(ID = c(1, 2, 3, 5),
                  Age = c(25, 30, 35, 40))

# 根据ID列进行右连接
merged_df <- merge(df1, df2, by = "ID", all.y = TRUE)
print(merged_df)

# 创建两个数据帧
df1 <- data.frame(ID = c(1, 2, 3, 4),
                  Name = c("Alice", "Bob", "Charlie", "David"))

df2 <- data.frame(ID = c(1, 2, 3, 5),
                  Age = c(25, 30, 35, 40))

# 根据ID列进行全连接
merged_df <- merge(df1, df2, by = "ID", all = TRUE)
print(merged_df)