Write right method to be concise

ruby-talk
1

there is a section of my program,it can run,
    require 'mysql'
    dbh = Mysql.real_connect("localhost", "root", "222222")
    days.times do #days=10000
    case code
    when "hk" then
        str="use dzh_hk"
        dbh.query(str)
        str_insert="insert into quote (code,date,price)values (?,?,?)
        st=dbh.prepare(str_insert)
        st.execute(data[0],data[1],data[2])
     when "sh" then
        str="use dzh_sk"
        dbh.query(str)
        str_insert="insert into quote (code,date,price)values (?,?,?)
        st=dbh.prepare(str_insert)
        st.execute(data[0],data[1],data[2])
     when "sz" then
        str="use dzh_sz"
        dbh.query(str)
        str_insert="insert into quote (code,date,price)values (?,?,?)
        st=dbh.prepare(str_insert)
        st.execute(data[0],data[1],data[2])
     end
    end
#others ommitted
   i feel it's burdensome，want to make it be concise, i writ a method
in my program

p1:
require 'mysql'
days.times do
  def myinsert(code,data)
    dbh = Mysql.real_connect("localhost", "root", "222222")
    str="use dzh_"+code
    dbh.query(str)
    str_insert="insert into quote (code,date,price)values (?,?,?)
    st=dbh.prepare(str_insert)
    st.execute(data[0],data[1],data[2])
  end
end
#others ommitted
Mysql::Error: Too many connections

p2:
require 'mysql'
dbh = Mysql.real_connect("localhost", "root", "222222")
days.times do
  def myinsert(code,data)
    str="use dzh_"+code
    dbh.query(str)
    str_insert="insert into quote (code,date,price)values (?,?,?)
    st=dbh.prepare(str_insert)
    st.execute(data[0],data[1],data[2])
  end
end
#others ommitted
NameError: undefined local variable or method `dbh' for main:Object

would you mind tell me to write a right method to make it be concise?

···

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2

Pen Ttt wrote in post #971751:

there is a section of my program,it can run,
    require 'mysql'
    dbh = Mysql.real_connect("localhost", "root", "222222")
    days.times do #days=10000
    case code
    when "hk" then
        str="use dzh_hk"
        dbh.query(str)
        str_insert="insert into quote (code,date,price)values (?,?,?)
        st=dbh.prepare(str_insert)
        st.execute(data[0],data[1],data[2])
     when "sh" then
        str="use dzh_sk"
        dbh.query(str)
        str_insert="insert into quote (code,date,price)values (?,?,?)
        st=dbh.prepare(str_insert)
        st.execute(data[0],data[1],data[2])
     when "sz" then
        str="use dzh_sz"
        dbh.query(str)
        str_insert="insert into quote (code,date,price)values (?,?,?)
        st=dbh.prepare(str_insert)
        st.execute(data[0],data[1],data[2])
     end
    end
#others ommitted
   i feel it's burdensome，want to make it be concise, i writ a method
in my program

p1:
require 'mysql'
days.times do
  def myinsert(code,data)
    dbh = Mysql.real_connect("localhost", "root", "222222")
    str="use dzh_"+code
    dbh.query(str)
    str_insert="insert into quote (code,date,price)values (?,?,?)
    st=dbh.prepare(str_insert)
    st.execute(data[0],data[1],data[2])
  end
end
#others ommitted
Mysql::Error: Too many connections

p2:
require 'mysql'
dbh = Mysql.real_connect("localhost", "root", "222222")
days.times do
  def myinsert(code,data)
    str="use dzh_"+code
    dbh.query(str)
    str_insert="insert into quote (code,date,price)values (?,?,?)
    st=dbh.prepare(str_insert)
    st.execute(data[0],data[1],data[2])
  end
end
#others ommitted
NameError: undefined local variable or method `dbh' for main:Object

would you mind tell me to write a right method to make it be concise?

You have several choices:

1. Pass dbh as an extra parameter to myinsert()

2. Make a wrapper class which holds the handle

class SqlHelper
  def initialize(dbh)
    @dbh = dbh
  end
  def myinsert(code,data)
    @dbh.query("use dhz_#{code}")
    ... etc
  end
end

sql = SqlHelper.new(dbh)
sql.myinsert(code, data)

3. Use a global variable ($dbh) to hold your database handle. This is
probably OK for a short script, but is poor practice when building a
large program.

···

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