我正试图使用 sqlSave() 将数据框上传到SQL Server的表中。这个数据框里有一个时间戳,我希望将它映射到SQL Server中的 datetime 列。
我遇到了两个问题:
1. 它会将数据框的时间戳映射为浮点数。
2. 它会创建一个表,但没有数据被上传,我得到了一个错误。
下面是一个示例数据框 mdf:
mdf <- structure(list(run = structure(c(1L, 1L, 1L, 1L, 1L, 1L), .Label = c("run_00",
"run_01", "run_02", "run_03", "run_04"), class = "factor"), slot = structure(c(1L,
1L, 1L, 1L, 1L, 1L), .Label = c("slot 3", "slot 4", "slot 5",
"slot 6"), class = "factor"), timestamp = structure(c(1320774563,
1320774624, 1320774686, 1320774747, 1320774809, 1320774871), class = c("POSIXct",
"POSIXt"), tzone = ""), channel = structure(c(1L, 1L, 1L, 1L,
1L, 1L), .Label = c("och01", "och02", "och09", "och10"), class = "factor"),
variable = structure(c(2L, 2L, 2L, 2L, 2L, 2L), .Label = c("num_blocks",
"num_collection", "num_corr_0", "num_corr_1", "num_uncorr_srow",
"post_fec_err_rate", "pre_fec_err_rate"), class = "factor"),
value = c(1, 62, 124, 185, 247, 309)), .Names = c("run",
"slot", "timestamp", "channel", "variable", "value"), row.names = c(NA,
6L), class = "data.frame")
> mdf
run slot timestamp channel variable value
1 run_00 slot 3 2011-11-08 12:49:23 och01 num_collection 1
2 run_00 slot 3 2011-11-08 12:50:24 och01 num_collection 62
3 run_00 slot 3 2011-11-08 12:51:26 och01 num_collection 124
4 run_00 slot 3 2011-11-08 12:52:27 och01 num_collection 185
5 run_00 slot 3 2011-11-08 12:53:29 och01 num_collection 247
6 run_00 slot 3 2011-11-08 12:54:31 och01 num_collection 309
当我尝试使用sqlSave将数据保存到SQL Server数据库时,以下是发生的情况...
> sqlSave(dbandle,mdf,tablename="mdf")
Error in sqlSave(dbandle, mdf, tablename = "mdf") :
[RODBC] Failed exec in Update
22018 0 [Microsoft][ODBC SQL Server Driver]Invalid character value for cast specification
此外,当我查看表的数据类型时,我没有看到时间戳的“datetime”类型。我不明白为什么RODBC会将POSIXct时间戳映射为除datetime之外的其他类型。
[rownames] [varchar](255) NULL,
[run] [varchar](255) NULL,
[slot] [varchar](255) NULL,
[timestamp] [float] NULL,
[channel] [varchar](255) NULL,
[variable] [varchar](255) NULL,
[value] [float] NULL
我该如何解决这个问题?