sqlsql-serverrsql-server-2008rodbc

RODBC sqlSave table creation problems

I'm having trouble creating a table using RODBC's sqlSave (or, more accurately, writing data to the created table).

This is different than the existing sqlSave question/answers, as

  1. the problems they were experiencing were different, I can create tables whereas they could not and
  2. I've already unsuccesfully incorporated their solutions, such as closing and reopening the connection before running sqlSave, also
  3. The error message is different, with the only exception being a post that was different in the above 2 ways

I'm using MS SQL Server 2008 and 64-bit R on a Windows RDP.

I have a simple data frame with only 1 column full of 3, 4, or 5-digit integers. 

> head(df)
                        colname
1                           564
2                          4336
3                         24810
4                         26206
5                         26433
6                         26553

When I try to use sqlSave, no data is written to the table. Additionally, an error message makes it sound like the table can't be created though the table does in fact get created with 0 rows.

Based on a suggestion I found, I've tried closing and re-opening the RODBC connection right before running sqlSave. Even though I use append = TRUE, I've tried dropping the table before doing this but it doesn't affect anything.

> sqlSave(db3, df, table = "[Jason].[dbo].[df]", append = TRUE, rownames = FALSE)
Error in sqlSave(db3, df, table = "[Jason].[dbo].[df]",  : 
  42S01 2714 [Microsoft][ODBC SQL Server Driver][SQL Server]There is already 
an object named 'df' in the database.
[RODBC] ERROR: Could not SQLExecDirect 'CREATE TABLE [Jason].[dbo].[df]  
("df" int)'

I've also tried using sqlUpdate() on the table once it's been created. It doesn't matter if I create it in R or SQL Server Management Studio, I get the error table not found on channel

Finally, note that I have also tried this without append = TRUE and when creating a new table, as well as with and without the rownames option.

Mr.Flick from Freenode's #R had me check if I could read in the empty table using sqlQuery and indeed, I can.

Update

I've gotten a bit closer with the following steps:

  1. I created an ODBC connection that goes directly to my Database within the SQL Server, instead of just to the default (Master) DB then specifying the path to the table within the table = or tablename = statements
  2. Created the table in SQL Server Management Studio as follows

GO

CREATE TABLE [dbo].[testing123]( [Person_DIMKey] [int] NULL ) ON [PRIMARY]

GO

  1. In R I used sqlUpdate with my new ODBC connection and no brackets around the tablename

  2. Now sqlUpdate() sees the table, however it complains that it needs a unique column

  3. Indicating that the only column in the table is the unique column with index = colname results in an error saying that the column does not exist

  4. I dropped and recreated the table specifying a primary key,

GO

CREATE TABLE [dbo].[jive_BNR_Person_DIMKey]( [jive_BNR_Person_DIMKey] [int] NOT NULL PRIMARY KEY ) ON [PRIMARY]

GO

which generated both a Primary Key and Index (according to the GUI interface of SQL Sever Management Studio) named PK__jive_BNR__2754EC2E30F848ED

  1. I specified this index/key as the unique column in sqlUpdate() but I get the following error:

Error in sqlUpdate(db4, jive_BNR_Person_DIMKey, tablename = "jive_BNR_Person_DIMKey", : index column(s) PK__jive_BNR__2754EC2E30F848ED not in database table

For the record, I was specifying the correct column name (not "colname") for index; thanks to MrFlick for requesting clarification.

Also, these steps are numbered 1 through 7 in my post but StackOverflow resets the numbering of the list a few times when it gets displayed. If anyone can help me clean that aspect of this post up I'd appreciate it.

Solution

  • After re-reading the RODBC vignette, here's the simple solution that worked:

    sqlDrop(db, "df", errors = FALSE)
sqlSave(db, df)

    Done.

    After experimenting with this a lot more for several days, it seems that the problems stemmed from the use of the additional options, particularlly table = or, equivalently, tablename =. Those should be valid options but somehow they manage to cause problems with my particular version of RStudio ((Windows, 64 bit, desktop version, current build), R (Windows, 64 bit, v3), and/or MS SQL Server 2008.

    sqlSave(db, df) will also work without sqlDrop(db, "df") if the table has never existed, but as a best practice I'm writing try(sqlDrop(db, "df", errors = FALSE), silent = TRUE) before all sqlSave statements in my code.