从R升序到MS SQL Server语法

问题描述

我希望能够使用Upsert，在这里我可以更新条件更改的现有行或在新行可用时追加新行。我想从R studio中进行编码，并与MS SQL Server配对。我使用虹膜数据集复制了以下工作流程。我想我快到了，但是不能完全完成SQL查询。另外，欢迎就工作流程提出建议。

> pacman::p_load(DBI,dbplyr,dplyr,odbc)
> 
> # Connection
> con <- DBI::dbConnect(odbc::odbc(),+                       Driver = "SQL Server",+                       Server = "localhost\\SQLEXPRESS",+                       Database = "master",+                       Trusted_Connection = "True")
> 
> Data.DWH <- dbReadTable(con,"iris") %>% 
+     unite("Lookup_Key",colnames(select(.,- ID)),remove = FALSE)
> 
> # Data in data warehouse
> head(Data.DWH)
              Lookup_Key Sepal.Length Sepal.Width Petal.Length Petal.Width Species ID
1 5.1_3.5_1.4_0.2_setosa          5.1         3.5          1.4         0.2  setosa  1
2   4.9_3_1.4_0.2_setosa          4.9         3.0          1.4         0.2  setosa  2
3 4.7_3.2_1.3_0.2_setosa          4.7         3.2          1.3         0.2  setosa  3
4 4.6_3.1_1.5_0.2_setosa          4.6         3.1          1.5         0.2  setosa  4
5   5_3.6_1.4_0.2_setosa          5.0         3.6          1.4         0.2  setosa  5
6 5.4_3.9_1.7_0.4_setosa          5.4         3.9          1.7         0.4  setosa  6
> 
> # New data example (created),1 entry to append,1 entry to ignore,1 entry to update
> 
> New.Data.Raw <- data.frame(stringsAsFactors=FALSE,+    Sepal.Length = c(5.1,1,4.9),+     Sepal.Width = c(3.5,2,3),+    Petal.Length = c(1.4,3,1.4),+     Petal.Width = c(2,4,0.2),+         Species = c("setosa","setosa","setosa"),+              ID = c(1,151,2)
+ ) %>% unite("Lookup_Key",remove = FALSE)
> 
> head(New.Data.Raw)
            Lookup_Key Sepal.Length Sepal.Width Petal.Length Petal.Width Species  ID
1 5.1_3.5_1.4_2_setosa          5.1         3.5          1.4         2.0  setosa   1
2       1_2_3_4_setosa          1.0         2.0          3.0         4.0  setosa 151
3 4.9_3_1.4_0.2_setosa          4.9         3.0          1.4         0.2  setosa   2
> 
> # Ready for insert/update
> # check for changes in the look up key (mash up of row values) or new entries according to ID
> New.Data <- New.Data.Raw %>% 
+     filter(!ID %in% Data.DWH$ID |
+                (ID %in% Data.DWH$ID & !Lookup_Key %in% Data.DWH$Lookup_Key))
> 
> head(New.Data)
            Lookup_Key Sepal.Length Sepal.Width Petal.Length Petal.Width Species  ID
1 5.1_3.5_1.4_2_setosa          5.1         3.5          1.4           2  setosa   1
2       1_2_3_4_setosa          1.0         2.0          3.0           4  setosa 151
>
> # Construct sql query for ms sql ===========================================================================
> 
> # construct columns for query - produces 1 string
> cols <- paste0('(',paste0(colnames(New.Data),collapse=','),')')
> 
> # construct values for query - produce 1 string
> vals <- paste0(
+     apply(New.Data,function(x) paste0("('",paste0(x,collapse = "','"),"')")),collapse = ",")
> 
> # construct update values for query
> insertVals <- paste0('(',paste0('s.',colnames(New.Data),')')
> 
> # construct update set for query
> updateSet <- paste0(colnames(New.Data%>%select(-ID)),+                     ' = s.',colnames(New.Data%>%select(-ID)),')
> 
> # construct upsert query (does not currently work!)
> queryNew.Data <- paste0('MERGE iris AS t ',+                             'USING (VALUES ',vals,') AS s',cols,+                             ' ON t.ID = s.ID ',+                             'WHEN MATCHED THEN ',+                             'UPDATE SET ',updateSet,+                             ' WHEN NOT MATCHED THEN ',+                             'INSERT',+                             ' VALUES',insertVals,';')
> 
> queryNew.Data <- gsub("\\b'\\b","",queryNew.Data) 
> queryNew.Data <- gsub("'NA'",'NULL',queryNew.Data)
> 
> # send the query to the database (no lucky currently)
> DBI::dbGetQuery(con,queryNew.Data)

解决方法

解决了这个问题，代码工作正常。只需修复列的命名约定。 SQL无法处理'。'在名称中输入，因此将其更改为“ _”，代码即可按需工作。