Case expression with subquery error: coud not be bound

Question

I'm trying to use a Case Expression when a I have a subquery, and SQL keeps me returning

The multi-part identifier "local1.DescricaoLotacao" could not be bound.

    CASE WHEN (SELECT local1.[DescricaoLotacao] FROM sgp.dbo.[LOTACAO] AS [local1]
                 WHERE local1.IdLotacao = (SELECT TOP 1 [uai].[IdLotacao] FROM sgp.dbo.[UnidadeAdministrativaInterna] AS [uai]
                                            WHERE uai.[CodigoPessoal] = p.[CodigoPessoal] AND uai.[DataFinal] IS NULL ORDER BY [uai].[DataInicial] DESC)
                                           ) IS NOT NULL
        THEN local1.[DescricaoLotacao]
        ELSE ''
    END,

I know it's why my local.descricaoLotacao is out of my parentheses. But I don't know how to fix it. I thing there is another way to do this kind of select.

Answer 1

If you are sure that the query will return only 1 row then instead of CASE use COALESCE() :

COALESCE(
  (
    SELECT local1.[DescricaoLotacao] FROM sgp.dbo.[LOTACAO] AS [local1]
    WHERE local1.IdLotacao = (
      SELECT TOP 1 [uai].[IdLotacao] 
      FROM sgp.dbo.[UnidadeAdministrativaInterna] AS [uai]
      WHERE uai.[CodigoPessoal] = p.[CodigoPessoal] AND uai.[DataFinal] IS NULL 
      ORDER BY [uai].[DataInicial] DESC
  ), 
  ''
)

Answer 2

I suggest using EXISTS This is assuming the local1.[DescricaoLotacao] portion exists outside of the CASE WHEN section.

CASE WHEN EXISTS (SELECT local1.[DescricaoLotacao] FROM sgp.dbo.[LOTACAO] AS [local1]
                 WHERE local1.IdLotacao = (SELECT TOP 1 [uai].[IdLotacao] FROM sgp.dbo.[UnidadeAdministrativaInterna] AS [uai]
                                            WHERE uai.[CodigoPessoal] = p.[CodigoPessoal] AND uai.[DataFinal] IS NULL ORDER BY [uai].[DataInicial] DESC)
                                           ) 
        THEN local1.[DescricaoLotacao]
        ELSE ''
    END