Wow, what a great feature. This saves me so much hacking! I planned on using virtual tables but per-query instance creation and parameter passing was going to be such a mess.
On Sun, Aug 23, 2015 at 1:55 PM, Richard Hipp <drh at sqlite.org> wrote: > On 8/23/15, Abilio Marques <abiliojr at gmail.com> wrote: > > > > 1. sqlite3 CLI doesn't seem to "load" the .so easily... The generated so > is > > called "lua.ext". If I run "*.load lua.ext*" it claims that there is no > .so > > available. I went into renaming the file to lua.so, and ran *.load > lua.so* > > ... Got: *Error: Shared object "lua.so.so <http://lua.so.so>" not found, > > required by "sqlite3"* ... then tried with *.load lua* ... I guessed that > > would work... but got *Error: Shared object "lua.so" not found, required > by > > "sqlite3*", even when the file was present at that directory... But then > I > > ran *.load ./lua.so* , and even *.load ./lua* ... both loaded without > > problems... Is that the correct behavior? > > Yes. You each have to specify a pathname or else the library must be > on LD_LIBRARY_PATH. I think this is a security restriction. Maybe > somebody else can shed more light on the matter. > > > > > 2. Which is the convention for the file extension of a loadable module? > .so > > and .dll?, or is there any other name used regularly among sqlite3 users? > > .so for linux. .dylib for mac. .dll for windows. > > You can just do ".load ./lua" without the suffix and SQLite will > supply the correct suffix for your platform. > > > > > > 3. Lua can return arrays. Also, Lua can return multiple values. Tried to > > take advantage of those facts, but while reading the SQLite API > > documentation, found no function where I could map multiple values as the > > return of a function. Am I wrong? For example: > > > > select * from table t where fieldA in (lua('return 1,2,3')); > > > > Could be a useful feat in real scripts with real code. > > > > Regular SQL functions always return scalars in SQLite. > > See https://www.sqlite.org/src/artifact/b8fb7befd85b3a9b for an > example of how to implement table-valued functions. This is a new > feature so there is no documentation on it yet. But the example is > well-commented. This capability will be in the next release, so > you'll have to compile from trunk if you want to use it right away - > it is not found in 3.8.11.1. > > -- > D. Richard Hipp > drh at sqlite.org > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
