Now it's possible to parse a command to load data from MS SQL. The
parser was until now parsing all database URI within the same common
rule and that isn't possible anymore if we want to distinguish in
between source database right from the parser, which we actually want to
do.
This patch also implement in-passing fixes all over the place, including
the transformation function float-to-string that only happened to work
on double-float data.
Converting the table definitions (with type casting) seems to work. Also
did experiment a little with actuallt fetching some data... and had to
edit the cl-mssql driver, which is temporarily monkey patched.
MySQL ENUM syntax is more complex than it first looked, allowing for
escaping and spaces, so use a more complex parser here. Fortunately, the
syntax looks like a CSV row enough that cl-csv can be re-used for that.
This allows users to benefit from the same flexible machinery when using
SQLite as when using MySQL, and also allows to add some more default
cast rules too.
The metabang-bind lib offers a nice bind macro that solves the problem
of ignoring bindings in destructuring-bind, and allows a let* approach
to nested destructuring (wven when mixed with let declarations).
Using that lib (that we already indirectly depend on anyway) simplifies
the parser code substantially.
It's not possible to use a comma separator when using more than one
source field option at the same time, and for better readability the
options are to be found enclosed in squared brackets.
Also, it's now possible to spell out "from" and "for" keywords on the
source definitions, making it easier to read and maintain the load file,
as in this full example:
(
a from 0 for 10,
b from 10 for 8,
c from 18 for 8,
d from 26 for 17 [null if blanks, trim right whitespace]
)
As seen in #116, it might be better for the users to be able to ask for
field trimming right in the source definition, like we do for processing
nulls.
