从AutoCompleteStringCollection删除重复c＃

Question

AutoCompleteStringCollection treatmentCollection = new AutoCompleteStringCollection(); 
if (con.State == ConnectionState.Closed) 
{ 
    con.Open(); 
} 
SqlCeCommand cmdTreatment = new SqlCeCommand("select Treatment from NewPatient", con); 
SqlCeDataReader readerTreatment = cmdTreatment.ExecuteReader(); 
if (readerTreatment.Read() == true) 
{ 
    while (readerTreatment.Read()) 
    { 
     treatmentCollection.Add(readerTreatment["Treatment"].ToString()); 
    } 
} 
comboBox2.AutoCompleteMode = AutoCompleteMode.Suggest; 
comboBox2.AutoCompleteSource = AutoCompleteSource.CustomSource; 
comboBox2.AutoCompleteCustomSource = treatmentCollection; 
if (con.State == ConnectionState.Open) 
{ 
    con.Close(); 
} 

我希望combobox2应该只有不同的值。 和组合框从treatmentCollection对象AutoCompleteStringCollection类 请帮助我？

Answer 1

替换：

select Treatment from NewPatient 

这样：

select distinct Treatment from NewPatient 

Answer 2

如果你只想要不同的值，你可以在你的SQL命令一样使用DISTINCT;

select DISTINCT Treatment from NewPatient 

退房Eliminating Duplicates with DISTINCT

Answer 3

我用用这个代码，它工作正常。

string query = @"Select distinct [FieldName] from [tableName]";