sql-排除空值

Question

如何刪除那些非值列？ 這是我的查詢：

SELECT CASE 
            WHEN region = 'CENTRAL'
               THEN 'Central' 
             WHEN region = 'EASTERN'
               THEN 'Eastern'   
               WHEN region = 'NORTHERN'
               THEN 'Northern' 
             WHEN region = 'SOUTHERN'
               THEN 'Southtern'               
  END as Peninsular , 
             case 
             WHEN region = 'BINTULU'
               THEN 'BINTULU' 
             WHEN region = 'KUCHING'
               THEN 'Kuching'   
               WHEN region = 'SIBU'
               THEN 'Sibu' 
   END as Sarawak,
            case 
             WHEN region = 'KOTA KINABALU'
               THEN 'KOTA KINABALU' 
             WHEN region = 'LAHAD DATU'
               THEN 'LAHAD DATU'  
               WHEN region = 'SANDAKAN'
               THEN 'SANDAKAN'
               WHEN region = 'TAWAU'
               THEN 'TAWAU'
   END as Sabah,
   region  
FROM locinvaisle
group by region

Answer 1

如果region是您的鍵值，請添加

...
FROM locinvaisle
WHERE region IS NOT NULL
...

Answer 2

SELECT CASE 
            WHEN region = 'CENTRAL'
               THEN 'Central' 
             WHEN region = 'EASTERN'
               THEN 'Eastern'   
               WHEN region = 'NORTHERN'
               THEN 'Northern' 
             WHEN region = 'SOUTHERN'
               THEN 'Southtern'               
  END as Peninsular , 
             case 
             WHEN region = 'BINTULU'
               THEN 'BINTULU' 
             WHEN region = 'KUCHING'
               THEN 'Kuching'   
               WHEN region = 'SIBU'
               THEN 'Sibu' 
   END as Sarawak,
            case 
             WHEN region = 'KOTA KINABALU'
               THEN 'KOTA KINABALU' 
             WHEN region = 'LAHAD DATU'
               THEN 'LAHAD DATU'  
               WHEN region = 'SANDAKAN'
               THEN 'SANDAKAN'
               WHEN region = 'TAWAU'
               THEN 'TAWAU'
   END as Sabah,
   region  
FROM locinvaisle
WHERE region is not null AND region != ''
group by region

取決於region是空還是空。

Answer 3

試試這個查詢。

添加此行

where region is not null AND region != ''

表名之后。

SELECT 
    CASE 
       WHEN region = 'CENTRAL' THEN 'Central' 
       WHEN region = 'EASTERN' THEN 'Eastern'   
       WHEN region = 'NORTHERN' THEN 'Northern' 
       WHEN region = 'SOUTHERN' THEN 'Southern'               
    END as Peninsular , 
    CASE
       WHEN region = 'BINTULU' THEN 'BINTULU' 
       WHEN region = 'KUCHING' THEN 'Kuching'   
       WHEN region = 'SIBU' THEN 'Sibu' 
    END as Sarawak,
    CASE
       WHEN region = 'KOTA KINABALU' THEN 'KOTA KINABALU' 
       WHEN region = 'LAHAD DATU' THEN 'LAHAD DATU'  
       WHEN region = 'SANDAKAN' THEN 'SANDAKAN'
       WHEN region = 'TAWAU' THEN 'TAWAU'
    END as Sabah,
    region  
FROM 
    locinvaisle 
WHERE
    region IS NOT NULL AND region != ''
GROUP BY
    region

Answer 4

添加條件...........

從locinvaisle所在的區域！=''