SQLite3 安裝及在Ruby下的使用

sudo apt-get install libsqlite3-dev
sudo gem install sqlite3-ruby-1.2.5.gem

不要安裝
sudo gem install sqlite3，如果已經安裝了要 sudo gem uninstall sqlite3進行卸載
這樣的話使用Ruby的時候會說找不到
SQLite3:Database.new

下面是一個使用SQLite3的例子

require 'rubygems'
require 'sqlite3'
begin
db = SQLite3::Database.new('mydata2.db')
result = db.execute("create table if not exists testtable
		   ( 
		   id INTEGER,
		   name string
		  ) ")

puts "before insert"
db.execute("insert into testtable values (1,'aaaa')")
#The following kind of select will return an array of ArrayWithTypeandFields
result = db.execute("select * from testtable")
if result.empty?
		puts "empty"
end
result.each do |x|
		puts x.fields[0],x.fields[1]
		puts x.types[0],x.types[1]
		puts x[0],x[1]
end


#The following kind of select will return a ResultSet
result = db.prepare("select sum(id) from testtable")
result.execute do |x|        
	puts x.columns
	x.each()do |value|
			puts value
	end
end

rescue SQLite3::CantOpenException => e
	puts "***********My God, open db error **********"
	puts e
end