# upsert gem

使用 [upsert gem](https://github.com/seamusabshere/upsert)
### 情境：
每天更新某個表，每次可能更新的數量眾多

### Upsert row

upsert = Upsert.new(connection, table_name)
data.each do |datum|
    upsert.row({ selector... }, { setter... })
end

### Upsesrt batch

Upsert.batch(connection, :table_name) do |upsert|
    data.each do |datum|
        upsert.row({ selector... }, { setter... })
    end
end

### BenchMark
全 insert 的例子 (683 rows)

                   user      system      total      real
upsert           0.150539   0.053402   0.203941 (  0.617650)
upsert batch     0.134048   0.041398   0.175446 (  0.868362)
SQL find/update  1.176058   0.148097   1.324155 (  1.682030)

全 update 的例子 (683 rows)

                   user      system      total      real
upsert           0.146811   0.050948   0.197759 (  0.895740)
upsert batch     0.128561   0.040608   0.169169 (  0.883774)
SQL find/update  1.146444   0.143768   1.290212 (  1.628095)