This code snippet appears to be part of a SQL...

This code snippet appears to be part of a SQL query that constructs a new field or column, likely in a SELECT statement. Here's what it does:

1. dpg2_seg: It uses the value of the field or column named dpg2_seg.

2. '|': This is a string literal containing the pipe (|) character, which is used as a separator.

3. mid(geo,2): The mid() function extracts a substring from the geo field starting from the second character (the 2 argument indicates the starting position).

4. dpg2_seg&'|'&mid(geo,2): The concatenation operator (&) joins the dpg2_seg value, the pipe (|), and the substring from geo.

5. as DPGGeoKey: The result of the concatenation is given the alias DPGGeoKey, which names the resulting column in the query output.

Example:

If dpg2_seg = "USA" and geo = "XNYC", then the result will be:

Result: "USA|NYC"

The new field DPGGeoKey will contain this concatenated value.

Purpose: This code is most likely used to create a key or identifier (DPGGeoKey) by combining parts of two different fields: dpg2_seg and a substring of geo, separated by a pipe (|).