Question

我们有一个来自SQL SERVER的数据库遗产，现在新的数据库是一个postgres，我想做一些测试，看看两个表中的内容是否相同，我仍然没有访问过遗留数据库（SQL服务器），我说通过轮询两个表来尝试使用新的postgres数据库并尝试比较数据，在迭代循环中我感到困惑，任何想法都会有所帮助：

require 'pg'
pg_conn = PGconn.connect("localhost", 5432, '', '', "myDB", "userxx", "Zazzz")

all_children = pg_conn.exec("SELECT * from COMPANY;") 
all_children2 = pg_conn.exec("SELECT * from COMPANY2;")

all_children.each do |child|
??????
end

谢谢，

Answer 1

快速而肮脏的方法是对一列进行快速检查，例如公司名称，并通过减去结果数组来比较结果以查看差异：

require 'pg'
pg_conn = PGconn.connect("localhost", 5432, '', '', "myDB", "userxx", "Zazzz")

all_children = pg_conn.exec("SELECT name from COMPANY;") 
all_children2 = pg_conn.exec("SELECT name from COMPANY2;")

# first check the count, if it's the same it's probably a good sign
puts all_children.length
puts all_children2.length

# check differences
results = all_children.uniq - all_children2.uniq
results2 = all_children2.uniq - all_children.uniq

对于更复杂的测试，您可以使用github上的科学家宝石：https://github.com/github/scientist

编辑： sql版本？

 select * from company left outer join company2 on company.name = company.name2 where company2.name is null;

ruby，postgres，比较来自两个数据库的两个表的数据

1 个答案: