[sqlite] accessing database from Lua and C

[Nelson, Erik - 2]

Simon Slavin wrote on Sunday, October 25, 2015 6:59 AM
> On 25 Oct 2015, at 10:05am, Lev  wrote:
> 
> > Untill now my architecture does all the SQLite work in C, and pass
> > simple variables on Lua's stack.
> >
> > Today morning I've got an idea to push only the database connection
> object.
> > The database is opened in the C code, however I only have a single
> > thread, so no other entity is accessing the database at the same time.
> 
> Can you use LuaSQLite3 or Lua-Sqlite3 to open a connection initially ?
> 
> 
> 
> 
> > Other solution would be to pass the filename of the database, but
> then
> > I have to close the connection. Must I?
> 
> You can have a C connection and a Lua connection at the same time, as
> long as you don't need to perform operations in both at the same time.
> 

I've had good luck compiling in lsqlite3, then registering the sqlite db handle 
into the Lua context using code like this

LuaIntf::LuaContext lua_context;
lua_context.importLibs();
sqlite3* db_handle = open_db_somehow();

if(1 == luaopen_lsqlite3(lua_context.state()))
   LuaIntf::Lua::popToGlobal(lua_context.state(), "sqlite3");
else
   throw runtime_error("error adding lsqlite3 to Lua context");

if(1 == lsqlite_do_open(lua_context.state(), NULL, db_handle))
   LuaIntf::Lua::popToGlobal(lua_context.state(), "db_name");
else
   throw runtime_error("error adding database to Lua context");


This example is using the excellent lua-intf library by Steve K. Chiu

https://github.com/SteveKChiu/lua-intf


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[sqlite] accessing database from Lua and C

[Lev]

Hi List,


I'm writing an application in native C that calls Lua scripts.

Untill now my architecture does all the SQLite work in C, and pass simple
variables on Lua's stack.

Today morning I've got an idea to push only the database connection object.
The database is opened in the C code, however I only have a single thread, so
no other entity is accessing the database at the same time.

Other solution would be to pass the filename of the database, but then I have
to close the connection. Must I?

I don't know if it is possible.

Thanks for your hints in advance.

Lev

-- 
73 de HA5OGL
Op.: Levente

[sqlite] accessing database from Lua and C

[Simon Slavin]

On 25 Oct 2015, at 10:05am, Lev  wrote:

> Untill now my architecture does all the SQLite work in C, and pass simple
> variables on Lua's stack.
> 
> Today morning I've got an idea to push only the database connection object.
> The database is opened in the C code, however I only have a single thread, so
> no other entity is accessing the database at the same time.

Can you use LuaSQLite3 or Lua-Sqlite3 to open a connection initially ?




> Other solution would be to pass the filename of the database, but then I have
> to close the connection. Must I?

You can have a C connection and a Lua connection at the same time, as long as 
you don't need to perform operations in both at the same time.

Simon.