1. suggestion for database.e
Hello,
I've added three functions, which I missed several times, to database.e
Are there any suggestions, or is there a better way to get the following
infos?
global function db_list()
-- return all open databases
return db_names
end function
-----
global function db_current()
-- return name of current selected database
if length(db_names) then return db_names[find(current_db,db_file_nums)]
else return -1 end if
end function
-----
global function db_current_table()
-- find a table, given its t_header
-- return table name
atom tables, nt, t_header, name_ptr
sequence tname
safe_seek(TABLE_HEADERS)
tables = get4()
safe_seek(tables)
nt = get4()
t_header = tables+4
for i = 1 to nt do
safe_seek(t_header)
name_ptr = get4()
safe_seek(name_ptr)
tname = get_string()
if t_header = current_table then
-- found it
return tname
end if
t_header += SIZEOF_TABLE_HEADER
end for
return -1
end function
bye
Markus
2. Re: suggestion for database.e
----- Original Message -----
From: "Markus Schaller" <markus.schaller at web.de>
To: "EUforum" <EUforum at topica.com>
Subject: suggestion for database.e
>
>
> Hello,
>
> I've added three functions, which I missed several times, to database.e
> Are there any suggestions, or is there a better way to get the following
> infos?
>
I'd had added the same functions to my copy of database.e too. I did the
current_table differently though.
I added a new variable 'current_table_name' and set this to "" whenever the
current_table is closed and to the table name when a table is selected. My new
routine is ...
global function db_current_table() -- DEREK PARNELL --
return current_table_name -- DEREK PARNELL --
end function -- DEREK PARNELL --
I also added a slight performance enhancement to db_select_table ...
global function db_select_table(sequence name)
-- let table with the given name be the current table
atom table, nkeys, index
atom block_ptr, block_size
integer blocks, k
table = table_find(name)
if table = -1 then
return DB_OPEN_FAIL
end if
if current_table = table then -- DEREK PARNELL --
return DB_OK -- DEREK PARNELL --
end if -- DEREK PARNELL --
current_table_name = name -- DEREK PARNELL --
current_table = table
. . .
--
Derek
