Question

我尝试检查空值或空列。

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

问题是，我想要包含几个表（myTable1，myTable2，myTable3）在同一个查询中，避免需要指定列名（myColumn）所以查询是通用的，尽可能在几个表中返回空列或空列名。

提前致谢。

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

SQL - 空或空字段

1 个答案: