ExecuteScalar 函数功能

OleDbCommand.ExecuteScalar Method  

MSDN 资料 

Executes the query, and returns the first column of the first row in the result set returned by the query. Additional columns or rows are ignored.

Namespace: System.Data.OleDb
Assembly: System.Data (in system.data.dll)

用处: 查询数据库总记录数

         string  querystr  =   " select count(*) From ConanMsg " ;
        OleDbCommand mycommand;
        mycommand  =   new  OleDbCommand(querystr, myconn);
         int  count  =  ( int )mycommand.ExecuteScalar();

count里保存的就是总记录数.