Problem in doing an update statement

Question

Hello all
i should write an update statement,
these tables : country: name,code,population,nextyearr_population ...
nextyear_population is empty,at first i should get population_growth from population table then calculate the next year population according to corrent population and population_growth
population: country(actually is code not name of country) ,population_growth,....
i wrote so and i got this error
Error starting at line 1 in command:
update country c
set c.nextyear_population=(c.population+ ((c.population*(select pop.population_growth from population pop join country co on co.code=pop.code))/100)
where country.code=population.country
Error at Command Line:4 Column:20
Error report:
SQL Error: ORA-00904: "POPULATION"."COUNTRY": invalid identifier
00904. 00000 -  "%s: invalid identifier"
*Cause:   
*Action:
--  File created - Wednesday-May-15-2013  
--  DDL for Table COUNTRY
  CREATE TABLE "intern"."COUNTRY" ("NAME" VARCHAR2(40), "CODE" CHAR(2), "CAPITAL" VARCHAR2(40), "PROVINCE" VARCHAR2(40), "POPULATION" NUMBER, "AREA" NUMBER, "NEXTYEAR_POPULATION" NUMBER)
   COMMENT ON COLUMN "intern"."COUNTRY"."NAME" IS 'the country name'
   COMMENT ON COLUMN "intern"."COUNTRY"."CODE" IS 'the internet country code (two letters)'
   COMMENT ON COLUMN "intern"."COUNTRY"."CAPITAL" IS 'the name of the capital'
   COMMENT ON COLUMN "intern"."COUNTRY"."PROVINCE" IS 'the province where the capital belongs to'
   COMMENT ON COLUMN "intern"."COUNTRY"."POPULATION" IS 'the population number'
   COMMENT ON COLUMN "intern"."COUNTRY"."AREA" IS 'the total area'
   COMMENT ON TABLE "intern"."COUNTRY"  IS 'the countries of the world with some data'
REM INSERTING into intern.COUNTRY
SET DEFINE OFF;
Insert into intern.COUNTRY (NAME,CODE,CAPITAL,PROVINCE,POPULATION,AREA,NEXTYEAR_POPULATION) values ('Andorra','ad','Andorra la Vella','Andorra la Vella',69865,468,null);
Insert into intern.COUNTRY (NAME,CODE,CAPITAL,PROVINCE,POPULATION,AREA,NEXTYEAR_POPULATION) values ('United Arab Emirates','ae','Abu Dhabi','Abu Dhabi',2523915,82880,null);
Insert into intern.COUNTRY (NAME,CODE,CAPITAL,PROVINCE,POPULATION,AREA,NEXTYEAR_POPULATION) values ('Afghanistan','af','Kabul','Kabul',28513677,647500,null);
--  File created - Wednesday-May-15-2013  
--  DDL for Table POPULATION
  CREATE TABLE "intern"."POPULATION" ("COUNTRY" CHAR(2), "POPULATION_GROWTH" NUMBER, "INFANT_MORTALITY" NUMBER)
   COMMENT ON COLUMN "intern"."POPULATION"."COUNTRY" IS 'the country code'
   COMMENT ON COLUMN "intern"."POPULATION"."POPULATION_GROWTH" IS 'population growth rate (percentage, per annum)'
   COMMENT ON COLUMN "intern"."POPULATION"."INFANT_MORTALITY" IS 'infant mortality (per thousand)'
   COMMENT ON TABLE "intern"."POPULATION"  IS 'information about the population of the countries'
REM INSERTING into intern.POPULATION
SET DEFINE OFF;
Insert into intern.POPULATION (COUNTRY,POPULATION_GROWTH,INFANT_MORTALITY) values ('ad',0.95,4.05);
Insert into intern.POPULATION (COUNTRY,POPULATION_GROWTH,INFANT_MORTALITY) values ('ae',1.54,14.51);
Insert into intern.POPULATION (COUNTRY,POPULATION_GROWTH,INFANT_MORTALITY) values ('af',4.77,163.07);thank you in advance
im using oracle11g and ubuntu 12
best,david

Answer 1

Hi, David,
Thanks for posting the CREATE TABLE and INSERT statements.
Don't forget to post the results you want from thatsample data (that is, the contents of country after everything is finished).
1003209 wrote:
... i wrote so and i got this error
Error starting at line 1 in command:
update country c
set c.nextyear_population=(c.population+ ((c.population*(select pop.population_growth from population pop join country co on co.code=pop.code))/100)
where country.code=population.country
Error at Command Line:4 Column:20
Error report:
SQL Error: ORA-00904: "POPULATION"."COUNTRY": invalid identifier
00904. 00000 -  "%s: invalid identifier"
In the UPDATE statement itself (outside of sub-queries) you can only reference the table being UPDATEd, but in the WHERE clause:
where country.code=population.countryyou're trying to reference another table, population. That's what caused the error.
You either need another sub-query, or MERGE, which will probably be simpler and more efficient than UPDATE.