Fixed issue 926 (problems with escaping table names for SQLite databases)

[NikNakk]

Fixed issues described with SQLite at https://github.com/hadley/dply/issues/926 by creating new function for db_insert_into that supports escaping (unlike the current DBI::dbWriteTable that was used) and using build_sql rather than paste0 within db_query_fields.

This was also raised at http://stackoverflow.com/questions/28132697/bracket-escaped-table-names-with-dplyr

[NikNakk]

Realised I'd not included the code to clear up resources (dbClearResult) from DBI::dbWriteTable; included now. It should be noted also that the db_insert_into.SQLiteConnection differs from the previous version in that it will never create a new table. At present, it's only called from copy_to which creates the table first anyway, and to my mind a function called db_insert_to generally should be appending into an existing table, with a separate call to create the table. If the previous behaviour is preferred, then additional code to call db_create_table as needed could be added.

[NikNakk]

Closed because was based on my master branch which made making any other changes problematic until this PR was successful

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/