先执行insert操作,SQL Server 2005数据库中的ID字段是自动生成的,然后我想获得这个自动生成的ID,应该怎么弄?DB是我的一个类库,其中DB.ExSql是执行的ExecuteNonQuery()操作,而DB.reDs()是执行SqlDataAdapter()操作。中间的桥梁是一个TimeID字段,是当前的时间。利用TimeID来作为维系这两个操作的纽带。问题是:在前两次的测试中,都可以取出ID值,但是后面就取不出来了,提示我DataRow中的0行没有数据。我又检查了下,发现insert操作没有成功,数据库中没有我要插入的数据。请问各位,这哪儿出错了?代码我贴出来了。我是新手,望大家多多指导。先谢谢了。
protected void btnTestWall_Click(object sender, EventArgs e)
{
string WallName = ddlWallName.SelectedValue.ToString();
string TestWallRe = txtTestWallRe.Text.Trim();
if (cb1.Checked)
{
string LayerName = txtLayerName1.Text.Trim();
float Thickness = Convert.ToSingle(txtThickness1.Text.Trim());
float SurfaceDensity = Convert.ToSingle(txtSD1.Text.Trim());
string Frgn_MT = txtMT1.Text.Trim();
float KongJing = Convert.ToSingle(txtKJ1.Text.Trim());
float ZhuangJK = Convert.ToSingle(txtZJK1.Text.Trim());
float CengLie = Convert.ToSingle(txtCL1.Text.Trim());
float GuBao = Convert.ToSingle(txtGB1.Text.Trim());
string Re = txtRe1.Text.Trim();
string TimeID = DateTime.Now.ToString("yyyymmddhhmmss");
string sqlinsert = string.Format("insert into TLayer (LayerName,Thickness,SurfaceDensity,Frgn_MT,KongJing,ZhuangJK,CengLie,GuBao,Re,TimeID) values ('{0}','{1}','{2}','{3}','{4}','{5}','{6}','{7}','{8}','{9}')", LayerName, Thickness, SurfaceDensity, Frgn_MT, KongJing, ZhuangJK, CengLie, GuBao, Re, TimeID);
DB.ExSql(sqlinsert);
string sqlselect = "select ID from TLayer where TimeID = '" + TimeID + "'";
DataSet ds = DB.reDs(sqlselect);
DataTable dt = ds.Tables[0];
DataRow dr = dt.Rows[0];
FrgnLayID_1 = Convert.ToInt32(dr[0]);
}
}
protected void btnTestWall_Click(object sender, EventArgs e)
{
string WallName = ddlWallName.SelectedValue.ToString();
string TestWallRe = txtTestWallRe.Text.Trim();
if (cb1.Checked)
{
string LayerName = txtLayerName1.Text.Trim();
float Thickness = Convert.ToSingle(txtThickness1.Text.Trim());
float SurfaceDensity = Convert.ToSingle(txtSD1.Text.Trim());
string Frgn_MT = txtMT1.Text.Trim();
float KongJing = Convert.ToSingle(txtKJ1.Text.Trim());
float ZhuangJK = Convert.ToSingle(txtZJK1.Text.Trim());
float CengLie = Convert.ToSingle(txtCL1.Text.Trim());
float GuBao = Convert.ToSingle(txtGB1.Text.Trim());
string Re = txtRe1.Text.Trim();
string TimeID = DateTime.Now.ToString("yyyymmddhhmmss");
string sqlinsert = string.Format("insert into TLayer (LayerName,Thickness,SurfaceDensity,Frgn_MT,KongJing,ZhuangJK,CengLie,GuBao,Re,TimeID) values ('{0}','{1}','{2}','{3}','{4}','{5}','{6}','{7}','{8}','{9}')", LayerName, Thickness, SurfaceDensity, Frgn_MT, KongJing, ZhuangJK, CengLie, GuBao, Re, TimeID);
DB.ExSql(sqlinsert);
string sqlselect = "select ID from TLayer where TimeID = '" + TimeID + "'";
DataSet ds = DB.reDs(sqlselect);
DataTable dt = ds.Tables[0];
DataRow dr = dt.Rows[0];
FrgnLayID_1 = Convert.ToInt32(dr[0]);
}
}
-------
create table #tb(id int identity(1,1),val varchar(20))
declare @id int
insert into #tb values('a')
select @id=@@identity
print @id
/*(1 行受影响)
1*/
/// 获取某表的某个字段的最大值
/// </summary>
/// <param name="FieldName">字段名</param>
/// <param name="TableName">表明</param>
/// <returns>返回最大值</returns>
public static int GetMaxID(string FieldName, string TableName)
{
string strsql = "select max(" + FieldName + ")+1 from " + TableName;
object obj = SqlHelper.GetSingle(strsql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
/// <summary>
/// 执行一条计算查询结果语句,返回查询结果(object)。
/// </summary>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果(object)</returns>
public static object GetSingle(string SQLString)
{
using (SqlCommand cmd = new SqlCommand(SQLString, GetConn()))
{
try
{
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (System.Data.SqlClient.SqlException e)
{
throw e;
}
} } /// <summary>
/// 带参数返回一行一列ExecuteScalar
/// </summary>
/// <param name="cmdtext">存储过程或者SQL语句</param>
/// <param name="para">参数数组</param>
/// <param name="ct">命令类型</param>
/// <returns>返回一行一列value</returns>
public static int ExecuteScalar(string cmdtext, SqlParameter[] para, CommandType ct)
{
int value;
try
{
cmd = new SqlCommand(cmdtext, GetConn());
cmd.CommandType = ct;
cmd.Parameters.AddRange(para);
value = Convert.ToInt32(cmd.ExecuteScalar());
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (cn.State == ConnectionState.Open)
{
cn.Close();
}
}
return value;
}