我有例如dataframe:
If-Range
看起来像这样:
df <- as.data.frame(matrix(sample(c(NA, 1:50), 49, replace = TRUE), 7))
现在我想将这个数据帧写入oracle数据库而不使用sqlSave ,因为我有一个巨大的data.frame,如果我这样做,R Studio会崩溃。相反,我决定用sqlQuery做到这一点:
V1 V2 V3 V4 V5 V6 V7
1 46 6 23 7 22 42 1
2 47 33 47 50 42 NA 49
3 14 35 49 48 37 10 22
4 42 23 5 4 41 46 48
5 32 36 24 26 19 31 45
6 26 47 28 19 34 19 32
7 37 13 46 46 NA 22 49
我已阅读this 帖子,但它对我不起作用。
这样做的最佳方式是什么?我想传递的字符串怎么样?提前谢谢。
答案 0 :(得分:2)
假设R dataframe列与Oracle中的列完全相同且顺序相同(不多或少),请考虑apply
至paste
collapse 每个列中的所有值行:
sqls <- sprintf("INSERT INTO MYTABLE VALUES (%s)",
apply(df, 1, function(i) paste(i, collapse=",")))
sqls
# [1] "INSERT INTO MYTABLE VALUES (2,10,9,50,34,37,29)"
# [2] "INSERT INTO MYTABLE VALUES (7,24,33,21,21,20,3)"
# [3] "INSERT INTO MYTABLE VALUES (39,38,2,33,43,33,7)"
# [4] "INSERT INTO MYTABLE VALUES (30,11,33,1,29,26,11)"
# [5] "INSERT INTO MYTABLE VALUES (50,45,13,27,3,35,36)"
# [6] "INSERT INTO MYTABLE VALUES (41,5,39,17,5,22,5)"
# [7] "INSERT INTO MYTABLE VALUES (21,50,39,30,2,11,49)"
# RECOMMENDED APPROACH TO SPECIFY COLUMNS
sqls <- sprintf("INSERT INTO MYTABLE (Col1, Col2, Col3, Col4, Col5, Col6, Col7) VALUES (%s)",
apply(df, 1, function(i) paste(i, collapse=",")))
connHandle <- odbcConnect("DBName", uid="user", pwd="password")
lapply(sqls, function(s) sqlQuery(connHandle, s))
close(connHandle)
更好的方法是使用RODBCext
参数化,只需传入没有循环的原始数据框:
library(RODBCext)
connHandle <- odbcConnect("DBName", uid="user", pwd="password")
query <- "INSERT INTO MYTABLE (Col1, Col2, Col3, Col4, Col5, Col6, Col7) VALUES (?, ?, ?, ?, ?, ?, ?)"
sqlExecute(connHandle, query, df)
odbcClose(connHandle)