我想在单行中添加两行的值

Question

我想在HYD中添加两个city_name＆＃39的值（HYD + HYDTC）

CITY_NAME    VALUE
  CCU         10
  CHI         12
  DEL         15
  HYD         20
  HYDTC       30
  MUM         10

我想以这种方式输出： -

CITY_NAME    VALUE  
  CCU         10
  CHI         12
  DEL         15
  HYD         50 
  MUM         10

Answer 1

如果要基于前三个字符合并行，则可以使用以下查询：

SELECT LEFT(CITY_NAME, 3) AS CITY_NAME, SUM(VALUE) AS VALUE
FROM mytable
GROUP BY LEFT(CITY_NAME, 3)

Answer 2

您可以使用CASE表达式。

<强>查询

select t.city_name_alt as city_name, sum(t.value) as value from(
    select city_name, 
    case city_name when 'HYDTC' then 'HYD' else city_name end as city_name_alt, 
    value
    from your_table_name
)t
group by t.city_name_alt;