怎样从数据库中读取时间C#

Question

C#操作数据库会吧，查询。。
select 时间 from tb where ..

Answer 1

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
 
namespace DatabaseOperate
{
    class SqlOperateInfo
    {
        //Suppose your ServerName is "aa",DatabaseName is "bb",UserName is "cc", Password is "dd"
        private string sqlConnectionCommand = "Data Source=aa;Initial Catalog=bb;User ID=cc;Pwd=dd";
        //This table contains two columns:KeywordID int not null,KeywordName varchar(100) not null
        private string dataTableName = "Basic_Keyword_Test";
 
        private string storedProcedureName = "Sp_InertToBasic_Keyword_Test";
        private string sqlSelectCommand = "Select KeywordID, KeywordName From Basic_Keyword_Test";
        //sqlUpdateCommand could contain "insert" , "delete" , "update" operate
        private string sqlUpdateCommand = "Delete From Basic_Keyword_Test Where KeywordID = 1";
 
        public void UseSqlReader()
        {
            SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.CommandType = System.Data.CommandType.Text;
            sqlCommand.Connection = sqlConnection;
            sqlCommand.CommandText = sqlSelectCommand;
 
            sqlConnection.Open();
            SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
            while(sqlDataReader.Read())
            {
                //Get KeywordID and KeywordName , You can do anything you like. Here I just output them.
                int keywordid = (int)sqlDataReader[0]; 
                //the same as: int keywordid = (int)sqlDataReader["KeywordID"]
                string keywordName = (string)sqlDataReader[1]; 
                //the same as: string keywordName = (int)sqlDataReader["KeywordName"]
                Console.WriteLine("KeywordID = " + keywordid + " , KeywordName = " + keywordName);
            }
 
            sqlDataReader.Close();
            sqlCommand.Dispose();
            sqlConnection.Close();
        }
        public void UseSqlStoredProcedure()
        {
            SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.CommandType = CommandType.StoredProcedure;
            sqlCommand.Connection = sqlConnection;
            sqlCommand.CommandText = storedProcedureName;
 
            sqlConnection.Open();
            sqlCommand.ExecuteNonQuery();
            //you can use reader here,too.as long as you modify the sp and let it like select * from ....
 
            sqlCommand.Dispose();
            sqlConnection.Close();
        }
        public void UseSqlDataSet()
        {
            SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.CommandType = System.Data.CommandType.Text;
            sqlCommand.Connection = sqlConnection;
            sqlCommand.CommandText = sqlSelectCommand;
 
            sqlConnection.Open();
            SqlDataAdapter sqlDataAdapter = new SqlDataAdapter();
            sqlDataAdapter.SelectCommand = sqlCommand;
            DataSet dataSet = new DataSet();
            //sqlCommandBuilder is for update the dataset to database
            SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);
            sqlDataAdapter.Fill(dataSet, dataTableName);
 
            //Do something to dataset then you can update it to Database.Here I just add a row
            DataRow row = dataSet.Tables[0].NewRow();
            row[0] = 10000;
            row[1] = "new row";
            dataSet.Tables[0].Rows.Add(row);
 
            sqlDataAdapter.Update(dataSet, dataTableName);
 
            sqlCommand.Dispose();
            sqlDataAdapter.Dispose();
            sqlConnection.Close();
        }
    }
}

Answer 2

select timeColumn from table_name不太明白楼主的问题。

Answer 3

select 字段 from 表名

Answer 4

            string str = this.TreeView1.SelectedNode.Text;
            string a = this.TextBox1.Text;
            string b = this.TextBox2.Text;
            DateTime c = DateTime.Parse(this.TextBox3.Text);
            string d = this.TextBox4.Text;
            db.open();
            try
            {
                string strinsert = "insert into " + str + " values ('" + a + "','" + b + "','" + c + "','" + d + "')";
                sqladap = new SqlDataAdapter(strinsert, db.sqlcon);
                sqladap.Fill(dt);
                GridView1.DataSource = dt;
                GridView1.DataBind();读取时间 这不是一摸一样的么。。

Answer 5

用ToLongTimeString()函数试一试。