Error when using copy_dm_to() on a table containing a string field with more than 255 characters

[tsilber21]

I was running into errors when trying to use copy_dm_to() on a dm containing a table with a string field that could exceed 255 characters. Note that I am copying the dm to an MSSQL database.

The error was a SQL error reading: String or binary data would be truncated.

After some digging, I believe the issue stems from the line in build_copy_queries(), which reads: tbl <- tbl_impl(ptype_dm, x)

It seems that it's trying to use the table with 0 rows to inform the column definitions, but this will assume VARCHAR(255) for any strings, even if that column contains a value of greater than 255 characters.

When I updated the line on my end to instead point at dm instead of ptype_dm to read tbl <- collect(tbl_impl(dm, x)) this seemed to fix the issue.

[krlmlr]

Thanks. Is this new in dm 1.0.7? Does dm 1.0.6 work?

Alternatively, can you try #2022?

CC @TSchiefer.

[krlmlr]

You could also try #2082. I might send that to CRAN before #2022.

[tsilber21]

Should've mentioned earlier that my dm is remote, is_src_db() returns TRUE. I'm copying from one remote source to another.

1.0.6 still has this issue, but if I rollback to version 1.0.5 then the copy is fine.

Neither #2022 nor #2082 solves the issue for this dm (same truncation error).

[krlmlr]

Oh, I see. I'll work on a fix in #2022 and #2082.

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