i have URL in db column "guid"

```
http://example.com/wp-content/uploads/2014/03/Waterproofing2.png

```

i need to change it to

```
http://example.com/blog/wp-content/uploads/2014/03/Waterproofing2.png

```

i need to replace all URL's with

```
http://example.com/wp-content/uploads/

```

to

```
http://example.com/blog/wp-content/uploads/

```