wnsrc/lua/includes/util/sql.lua

--[[
| This file was obtained through the combined efforts
| of Madbluntz & Plymouth Antiquarian Society.
|
| Credits: lifestorm, Gregory Wayne Rossel JR.,
| 	Maloy, DrPepper10 @ RIP, Atle!
|
| Visit for more: https://plymouth.thetwilightzone.ru/
--]]


-- Return if there's nothing to add on to
if ( !sql ) then return end


--[[----------------------------------------------------------
	Attempts to make a string safe to put into the database
------------------------------------------------------------]]
function sql.SQLStr( str_in, bNoQuotes )

	local str = tostring( str_in )

	str = str:gsub( "'", "''" )

	local null_chr = string.find( str, "\0" )
	if ( null_chr ) then
		str = string.sub( str, 1, null_chr - 1 )
	end

	if ( bNoQuotes ) then
		return str
	end

	return "'" .. str .. "'"
end

SQLStr = sql.SQLStr


--[[---------------------------------------------------------
	Returns true if the table exists. False if it doesn't
-----------------------------------------------------------]]
function sql.TableExists( name )

	local r = sql.Query( "SELECT name FROM sqlite_master WHERE name=" .. SQLStr( name ) .. " AND type='table'" )

	return r and true or false

end

--[[---------------------------------------------------------
	Returns true if the index exists. False if it doesn't
-----------------------------------------------------------]]
function sql.IndexExists( name )

	local r = sql.Query( "SELECT name FROM sqlite_master WHERE name=" .. SQLStr( name ) .. " AND type='index'" )

	return r and true or false

end

--[[---------------------------------------------------------
	Query and get a single row
	eg sql.QueryRow( "SELECT * from ratings LIMIT 1" )
-----------------------------------------------------------]]
function sql.QueryRow( query, row )

	row = row or 1

	local r = sql.Query( query )

	if ( r ) then return r[ row ] end

	return r

end

--[[---------------------------------------------------------
	Query and get a single value
	eg sql.QueryValue( "SELECT count(*) from ratings" )
-----------------------------------------------------------]]
function sql.QueryValue( query )

	local r = sql.QueryRow( query )

	if ( r ) then

		-- Is this really the best way to get the first/only value in a table
		for k, v in pairs( r ) do return v end

	end

	return r

end

--[[---------------------------------------------------------
	Call before lots of inserts (100+), will hold off writing to disk
	until Commit is called, which will increase performance (a lot)
-----------------------------------------------------------]]
function sql.Begin()
	sql.Query( "BEGIN;" )
end


--[[---------------------------------------------------------
	See Above
-----------------------------------------------------------]]
function sql.Commit()
	sql.Query( "COMMIT;" )
end


--[[----------------------------------------------------------
	m_strError is set by the dll
------------------------------------------------------------]]
function sql.LastError()
	return sql.m_strError
end