spec_meta_column_info
dbColumnInfo()
returns a data frame
with at least two columns "name" and "type" (in that order)
(and optional columns that start with a dot).
The "name" and "type" columns contain the names and types
of the R columns of the data frame that is returned from DBI::dbFetch().
The "type" column is of type character and only for information.
Do not compute on the "type" column, instead use dbFetch(res, n = 0)
to create a zero-row data frame initialized with the correct data types.
An attempt to query columns for a closed result set raises an error.
A column named row_names is treated like any other column.
The column names are always consistent
with the data returned by dbFetch().
If the query returns unnamed columns,
non-empty and non-NA names are assigned.
Column names that correspond to SQL or R keywords are left unchanged.
Other meta specifications:
spec_get_info,
spec_meta_bind,
spec_meta_get_row_count,
spec_meta_get_rows_affected,
spec_meta_get_statement,
spec_meta_has_completed,
spec_meta_is_valid