sql - SQL 中的转换日期错误

Question

执行以下动态 SQL 语句时，出现错误:

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

[ReturnDate] 定义为 datetime，@FromDate 和 @ToDate 参数作为类型传递日期时间也是如此。我缺少什么？

Set @SQLString = 
   'Select 
        [ID], [ReturnDate], [PolicyNumber]
    From 
        Bil_ReturnsRepository   
    Where
        (' + @PolicyNumber + ' is null or  PolicyNumber =  (' + @PolicyNumber + ')) 
        and (ReturnDate) >= Convert(date, ' + @FromDate + ')) 
        and (ReturnDate) <= Convert(date, ' + @ToDate + '))
        and PaymentAmount > 0.00'

Answer 1

您可能正在使用 SQL Server。如果是这样，请学习使用sp_executesql 。它的功能之一是能够传递参数:

Set @SQLString = '
Select [ID], [ReturnDate], [PolicyNumber]
From Bil_ReturnsRepository   
Where (@PolicyNumber is null or PolicyNumber = @PolicyNumber) and
      (ReturnDate >= @p_FromDate) and
      (ReturnDate <= @p_ToDate) and
      PaymentAmount > 0.00
';

declare @p_fromdate date;
declare @p_todate date;

select @p_fromdate = convert(date, @fromdate),
       @p_todate = convert(date, @todate);

exec sp_executesql @sql,
                   N'@p_fromdate date, @p_todate date, @policynumber int',
                   @p_fromdate=@p_fromdate, @p_todate=@p_todate, @policynumber=@policynumber;

如果 @fromdate 和 @todate 已经具有变量 @p_fromdate 和 @p_todate 则不需要正确的类型。