Replacing NAs in column with values from another table SQL Server -

this first time posting stack overflow , know similar questions have been asked before, apologize in advance. however, can't seem work around regardless of solutions given in other forums.

i have 2 tables in sql server, 1 contains storm event info , other contains county info. both contain identical county_fips numbers. neither of these contain primary or foreign keys.

i need replace nas storm event info lat/lons county table. possible without foreign/primary key relationships?

the stormevent table looks this:

id | lat | lon | state_fips | county_fips  ------------------------------------------ 1  |  33 | -88 |    028     |    087 2  |  31 | -98 |    048     |    225 3  |  na |  na |    017     |    034 4  | 39  | -100|    020     |    063 

and on...

the countytable looks (statefp10, countyfp10 = fips; intptlat10, intptlon10 = lat/lon):

  statefp10 | county_fp10   | state_fp10| intptlat10 | intptlon10    --------------------------------------------------------------     1       |  087          | 028       |    33      |  -88     2       |  225          | 048       |    31      |  -98          3       |  034          | 017       |    45      |  -102 

and on.

so far i've tried following code adjust lat column slight variations:

update n  set n.lat= c.intptlat10 stormevent n  inner join countytable c on n.county_fips= c.countyfp10 n.lat = 'na'  

the query executed, , i'm told x amount of rows affected, when write select statement retrieve of nas included in lats stormevent table, still there.

if can point me in right direction appreciated! again, apologize if going wrong way, first post , sql novice.

you may need update join. i've created table variables test with.

declare @stormevent table (id int, lat varchar(10), lon varchar(10),                              state_fips int, county_fips int) insert @stormevent (id , lat, lon, state_fips, county_fips) values  (1,'33','-88',028,087),         (2,'31','-98',048,225),         (3,'na','na',017,034),         (4,'39','-100',020,063)   declare @countytable table (statefp10 int, county_fp10   int, state_fp10 int,                              intptlat10 varchar(10), intptlon10 varchar(10)) insert @countytable values  (1,087,028,'33','-88'),         (2,225,048,'31','-98'),         (3,034,017,'45','-102')  update n  set n.lat= c.intptlat10, n.lon = c.intptlon10 @stormevent n  inner join @countytable c on n.state_fips= c.state_fp10 n.lat = 'na'  select * @stormevent 

assuming want both n/a values updated, add lon column update.

set n.lat = c.intptlat10, n.lon = c.intptlon10 

results:

id  lat lon     state_fips   county_fips 1   33  -88     28           87 2   31  -98     48           225 3   45  -102    17           34 4   39  -100    20           63