Using BASH, I need to transform the csv output I receive from a data source into a different format to make it easier to import into SQL server.

The source format is a single row with one data point then a comma then any number of hosts separated by a colon.

The target format is a data point then a comma then one of the hosts on a line. Then the next line would be the same data point then a comma then the next host.

Basically I need to change from 1 row per data point and numerous colon separated hosts to multiple rows per data point, with only one of the hosts per row

Source format:

```
data1,host1:host2
data2,host4:host5:host6
data3,host4:host7:host1:host5:host9

```

I need

```
data1,host1
data1,host2
data2,host4
date2,host5
data2,host6
data3,host4
data3,host7
data3,host1
data3,host5
data3,host9

```