ruby数据库

Ⅰ rails on ruby，如何缓存数据库到本地

可以采用cookie来保存数据，想要提交信息的时候在对服务器发出请求

Ⅱ ruby（rails) 程序如何 连接 各种远程数据库

在使用Cookie.find等操作的时候，就会连接到database.yml中monitor_spider配置的数据库上操作。以前一直都这么用，没发现什么不妥。最近一个项目，由于启动的进程比较多，老是碰到数据库连接池链接获取超时的错误。

通过MySQL Client用命令:show processlist; 发现数据库连接数量一直居高不下，轻轻松松就上2k+的连接。通过读Rails框架的connection_pool.rb文件代码，发现在各模型中用establish_connection连接数据库会造成很大的问题。文件中类ConnectionHandler的establish_connection方法代码如下：Ruby代码 def establish_connection(name, spec) @connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec) end def establish_connection(name, spec)

@connection_pools[name] = ConnectionAdapters::ConnectionPool.new(spec)

Ⅲ 如何用ruby操作sql数据库

可以看一下这个网页
http://www.cnblogs.com/wangyuyu/p/3242611.html
详细讲了
用ruby操作sql数据库

Ⅳ 如何使用Ruby on Rails连接Oracle数据库

今天学习了一下最近流行的Ruby on Rails，感觉：就是一个代码生成器
链接Oracle数据库的时候，查了半天的资料。终于找到办法了
http://blog.csdn.net/OwenLiu/article/details/576715

Ⅳ ruby 可以连hana 数据库吗

可以的，具体步骤如下，以及例子代码，用ODBC

1. Install Sinatra on Ruby

   gem install sinatra

2. Install DevKit forRuby

   rubydk.rb init
rubydk.rb install

3.Install RDBIgem install rdbi-driver-odbc

4.Creating an 32bit ODBCGo to C: –> Windows –> SysWOW64 –> odbcad32.exe

5.

Ruby_SAP_HANA.rb

require ‘sinatra’

require ‘rdbi-driver-odbc’

get ‘/’ do

body do

<<-eos

<div align=’center’>

<h1>Ruby/Sinatra and SAPHANA– Table Browser</h1>

<form action=’/login’ method=’post’>

<label for=’dsn’>DSN</label><br/>

<input type=’text’ name=’dsn’ /><br />

<label for=’user’>User</label><br />

<input type=’text’ name=’user’ /><br />

<label for=’password’>Password</label><br />

<input type=’password’ name=’password’ /><br />

<input type=’submit’ name=’submit’ value=’Login’ />

</form>

</div>

eos

end

end

get ‘/login_view’ do

$output = “<div align=’center’><form action=’/table_view’ method=’post’>”

$output += “Choose Table <SELECT NAME=’tab’>”

for i in 0…$Tables_Len

$output += “<option value=#{$Tables[i]}>#{$Tables[i]}</option>”

end

$output += “</option>”

$output += “<input type=’submit’ name=’submit’ value=’Show Table’ />”

$output += “</form></div>”

body $output

end

get ‘/show_table’ do

$output = “<div align=’center’><table border=’1′><tr>”

for i in 0…$Fields_Len

$Fields_Fields = $Fields[i].to_s

$output += “<th> #{$Fields_Fields} </th>”

end

$output += “</tr>”

for i in 0…$Data_Len

$output += “<tr>”

for j in 0…$Fields_Len

$output += “<td> #{$Data[i][j].to_s} </td>”

end

$output += “</tr>”

end

$output += “</table></div>”

body $output

end

post ‘/login’ do

$dsn,$user,$password = params[:dsn],params[:user],params[:password]

“#{do_login}”

“#{get_tables}”

redirect ‘/login_view’

end

post ‘/table_view’ do

$tab = params[:tab]

“#{get_data}”

redirect ‘/show_table’

end

helpers do

def do_login

$dbh = RDBI.connect :ODBC, :db => $dsn, :user => $user,:password => $password

end

def get_tables

$rs = $dbh.execute “SELECT table_name from SYS.CS_TABLES_ where schema_name = ‘SFLIGHT'”

$ary = $rs.as(:Array).fetch(:all)

$Tables = Array.new

for i in 0…$ary.length

$Tables.push($ary[i][0])

end

$Tables_Len = $Tables.length

end

def get_data

$query = “SELECT COLUMN_NAME FROM SYS.CS_COLUMNS_ AS A INNER JOIN SYS.CS_TABLES_ AS B “

$query += “ON A.TABLE_REF = B.REF_ID WHERE TABLE_NAME = ‘”

$query += $tab

$query += “‘ AND ABAP_TYPE_ID > 0”

$rs = $dbh.execute $query

$ary = $rs.as(:Array).fetch(:all)

$Fields = Array.new

$Data = Array.new

for i in 0…$ary.length

$Fields.push($ary[i][0])

end

$Fields_Len = $Fields.length

$query = “SELECT * FROM SFLIGHT.” + $tab

$rs = $dbh.execute $query

$ary = $rs.as(:Array).fetch(:all)

for i in 0…$ary.length

$Data.push($ary[i])

end

$Data_Len = $Data.length

end

end

Ⅵ ruby连接sqlite,ruby中创建数据库sample，往表格student中插数据，update方法，键盘输入，修改对应值

每个方法都加参数 db
然后各个方法里面对db进行连接，然后才是每个方法相应的操作

Ⅶ Ruby on Rails 查询数据库 where 和 find 的区别

在写LINQ语句的时候，往往会看到版.AsEnumerable() 和 .AsQueryable() 。
例如：权
[csharp] view plain
string strcon = "Data Source=.\\SQLEXPRESS;Initial Catalog=Db_Example;Persist Security Info=True;User ID=sa;Password=sa";
SqlConnection con = new SqlConnection(strcon);
con.Open();

Ⅷ ruby 连接数据库mysql 报错~~~

require 'mysql'
class MysqlDb
# attr_accessor :host, :user, :pass, :database
def open(host=nil, user=nil, pass=nil, database=nil,port=3306)
@host =host
@user = user
@pass = pass
@database = database
@port = port
begin
@connection = Mysql.new(@host, @user, @pass, @database, @port)
rescue
puts "connect faild! an error has occurred: #{$!}" # 错误信息保存在特殊变量$!中。
try_again
end
end

def try_again
puts '------------------try again, if not modify, leave a blank---------------'
print "host: "
host=STDIN.gets.strip
@host = check_value(host,@host)
puts "---------------current host: #{@host}"
print "user: "
user =STDIN.gets.strip
@user = check_value(user,@user)
puts "---------------current user: #{@user}"
print "password: "
pass =STDIN.gets.strip
@pass = check_value(pass,@pass)
puts "---------------current password: #{@pass}"
print "database: "
database =STDIN.gets.strip
@database = check_value(database,@database)
puts "---------------current database: #{@database}"
print "port: "
port =STDIN.gets.strip
@port = check_value(port,@port)
open(@host, @user, @pass, @database, @port)
puts "---------------current port: #{@port}"
end
def check_value(value,returnvalue)
if value == ""
nil
else
returnvalue = value
end
return returnvalue
end

def iquery(sql)
field = []
@connection.query(sql).each do |data|
field << data
end
field.to_a
end
def iexecute(sql)
@connection.query(sql)
end
def close
@connection.close
end

end

# useages
adb = MysqlDb.new
adb.open('127.0.0.1','root','zyq001122','hello_z','3307')
# result = db.query "insert into user value(7,\"lilY\",\"256y42\",\"#{Time.now.strftime("%Y-%m-%d %H:%M:%S")}\" )" # 插入记录
# result.each {|row| puts row}
num_of_records = adb.iquery ('select count(*) from user') #查询
puts num_of_records
#sql = "insert into user value(10,\"Hello-Kitty\",\"256y42\",\"#{Time.now.strftime("%Y-%m-%d %H:%M:%S")}\" )" # 数据操作
# sql = 'update user set name=\'jackjhons\' where uid=5 ' # 更新一条记录
#adb.iexecute(sql)
# adb.close

Ⅸ ruby on rails 可否将一个form中的数据提交给3数据库

表单跟数据库没关系, 看你在controller里怎么处理. 在controller里操作就可以了.

Ⅹ 安装ruby环境，用mysql数据库，总是报错，调了一下午，网上方法都用了也不管事

make的时候需要调用ruby很多编译前的参数.一些信息make不知道的话会不知道如何建库.
我个人的建议是根据你安装的ruby路径和版本信息把配置选项补充全.下面是我电脑上面的配置,你可以借鉴一下.据我分析应该能解决你的问题.
Provided configuration options:
--with-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/usr/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/local/ruby-2.1.2/rubies/ruby-2.1.2/bin/ruby