[英]C# LINQ Dynamic Select with all type of data
I am implementing search by using dynamic LINQ, where the query gets column name and search value in runtime. 我正在使用动态LINQ实现搜索,其中查询在运行时获取列名和搜索值。 In this way, I need to parse the data according to the column type-
这样,我需要根据列类型解析数据-
if (isNumeric)
{
int x = Int32.Parse(txtHistorySearch.Text);
truncatedData = ((IQueryable<object>)rawData).Where(columnName + "=@0", x).ToList();
}
else if (DateTime.TryParse(txtHistorySearch.Text, out temp))
{
var parsedDt = DateTime.Parse(txtHistorySearch.Text);
var nextDay = parsedDt.AddDays(1);
truncatedData = ((IQueryable<object>)rawData).Where(columnName + ">= @0 && " + columnName + " < @1", parsedDt, nextDay).ToList();
}
else
{
truncatedData = ((IQueryable<object>)rawData).Where(columnName + "=@0", searchValue).ToList();
}
Can this be done for all data types using single where clause? 可以使用单个where子句为所有数据类型完成此操作吗?
You can do this using expression trees. 您可以使用表达式树来执行此操作。
https://msdn.microsoft.com/en-us/library/bb397951.aspx https://msdn.microsoft.com/en-us/library/bb397951.aspx
https://msdn.microsoft.com/en-us/library/bb882637.aspx https://msdn.microsoft.com/en-us/library/bb882637.aspx
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