When on the client side you specify co/coro/combo columns (combo-box/select) in the grid, the grid will automatically request data for them in the same manner as for the filtering options.
By default, the grid will use DISTINCT select against the related field, and fetch all possible options.
If you need to define a custom list of options, you can use one of 2 ways:
<cfset param = structNew()>
<cfset param["1"] = "one">
<cfset param["2"] = "two">
<cfset param["3"] = "three">
<!--- param[value] = label --->
<cfset grid.set_options("item_nm",param)>
<cfset grid.render_table("grid50","item_id","item_nm,item_cd")>
<cfset list = createObject(
"component",
"dhtmlxConnectors.OptionsConnector"
).init("#datasource#","MySQL")>
<cfset list.render_table(
"countries",
"country_id",
"country_id(value),country_name(label)"
)>
<cfset grid.set_options("item_nm",list)>
<cfset grid.render_table("grid50","item_id","item_nm,item_cd")>
co/combo type
coro type: