sql - 使用 DateTime 列的 CASE 语句

Question

我的查询中有一个日期时间列，我想在这个查询中做一个 CASE。

如果 DateDelivered 列不为空，则显示日期，否则显示字符串 'Pendent'我该怎么做？

CASE WHEN DateDelivered IS NOT NULL THEN DateDelivered ELSE 'Pendent' END AS DateDelivered 2

我收到了这个错误

Conversion failed when converting date and/or time from character string.

整个查询

SELECT  San_Imovel.Imovel_Id ,
        San_Chave.DataHoraPegou ,
        CASE WHEN San_Chave.DateDelivered IS NOT NULL THEN San_Chave.DateDelivered
             ELSE ISNULL(CAST(San_Chave.DateDelivered AS VARCHAR), 'Pendent')
        END AS DateDelivered2 ,
        San_Usuario.NomeCompleto + ' - ' + sc.Apelido AS Nome ,
        San_Cliente.NomeCompleto AS NomeCliente ,
        San_Credenciada.Apelido ,
        San_Cliente.Cliente_Id ,
        San_ChaveImovel.QuantidadeChave
FROM    San_ChaveImovel
        JOIN San_Chave ON San_ChaveImovel.Chave_Id = San_Chave.Chave_Id
        JOIN San_Credenciada ON San_Chave.Credenciada_Id = San_Credenciada.Credenciada_Id
        JOIN San_Imovel ON San_ChaveImovel.Imovel_Id = San_Imovel.Imovel_Id
        JOIN San_Usuario ON San_Chave.Usuario_Id_Responsavel = San_Usuario.Usuario_Id
        JOIN San_Credenciada sc ON San_Usuario.Credenciada_Id = sc.Credenciada_Id
        JOIN San_Cliente ON San_Chave.Cliente_Id = San_Cliente.Cliente_Id  

Answer 1

您正在尝试将“Pendent”转换为 DateTime，因为它会将所有数据转换为相同的数据类型。此外，如果您只是检查 NULL，则可以使用 ISNULL 或 COALESCE。试试这个:

ISNULL(CAST(DateDelivered AS VARCHAR), 'Pendent')

您还可以指定 DateDelivered 的格式:

ISNULL(CONVERT(VARCHAR, DateDelivered, 101), 'Pendent')

查看 101 here 的更多选项.