SQL - 空或空字段

Question

我试图检查空值或空列。

SELECT * FROM myTable 
WHERE myColumn IS NULL OR myColumn = ' '; 

的事情是，我想包括几桌（MYTABLE1，myTable2，myTable3）在同一查询 和避免需要指定列名（myColumn） 所以查询是通用尽可能恢复几个表中的空列名或空列名。

在此先感谢。

Answer 1

DECLARE @col VARCHAR(255), 
     @table VARCHAR(255), 
     @cmd VARCHAR(max) 
DECLARE getinfo CURSOR FOR 
    SELECT t.name, 
     c.name 
    FROM sys.tables t 
     JOIN sys.columns c 
      ON t.Object_ID = c.Object_ID 
    WHERE t.Name IN ('table-1', 'table-2') 

--WHERE t.Name IN (provide your TABLE list) 
OPEN getinfo 

FETCH NEXT FROM getinfo INTO @table, @col 

WHILE @@FETCH_STATUS = 0 
    BEGIN 
     SELECT @cmd = 'IF EXISTS (SELECT top 1 * FROM ' + @table 
        + ' WHERE (' + @col + ' IS NULL or ' + @col 
        + '='''')) BEGIN print ''tablename=''+''' 
        + @table + '''+'' column name=''+''' + @col 
        + ''' end' 

     --PRINT @cmd 

     EXEC(@cmd) 
     FETCH NEXT FROM getinfo INTO @table, @col 
    END 

CLOSE getinfo 

DEALLOCATE getinfo