本文转载：http://blog.csdn.net/limlimlim/article/details/8638080
#region 多条件搜索时，使用List集合来拼接条件（拼接Sql）
StringBuilder sql = new StringBuilder("select * from PhoneNum");
List<string> wheres = new List<string>();
if (cboGroup.SelectedIndex != 0)
{
wheres.Add(" ptypeid=" + cboGroup.Text.Split('|')[0]);
}
if (txtSearchName.Text.Trim().Length > 0)
{
wheres.Add(" pname like '%" + txtSearchName.Text.Trim() + "%'");
}
if (txtSearchCellPhone.Text.Trim().Length > 0)
{
wheres.Add(" pcellphone like '%" + txtSearchCellPhone.Text.Trim() + "%'");
}
//判断用户是否选择了条件
if (wheres.Count > 0)
{
string wh = string.Join(" and ", wheres.ToArray());
sql.Append(" where " + wh);
}
#endregion
#region 多条件搜索使用带参数的sql语句
StringBuilder sql = new StringBuilder("select * from PhoneNum");
List<string> wheres = new List<string>();
List<SqlParameter> listParameter = new List<SqlParameter>();
if (cboGroup.SelectedIndex != 0)
{
wheres.Add(" ptypeid=@typeid ");
listParameter.Add(new SqlParameter("@typeid", cboGroup.Text.Split('|')[0]));
}
if (txtSearchName.Text.Trim().Length > 0)
{
wheres.Add(" pname like @pname ");
//pname like '%乔%'
//pname liek '%'+@pname+'%'
listParameter.Add(new SqlParameter("@pname", "%" + txtSearchName.Text.Trim() + "%"));
}
if (txtSearchCellPhone.Text.Trim().Length > 0)
{
wheres.Add(" pcellphone like @cellphone ");
listParameter.Add(new SqlParameter("@cellphone", "%" + txtSearchCellPhone.Text.Trim() + "%"));
}
//判断用户是否选择了条件
if (wheres.Count > 0)
{
string wh = string.Join(" and ", wheres.ToArray());
sql.Append(" where " + wh);
}
SqlHelper.ExecuteDataTable(sql.ToString(), listParameter.ToArray());
#endregion
推荐C#中一套生成sql条件的类
http://dotnet.chinaitlab.com/CSharp/746379_3.html
http://blog.csdn.net/dj1232090/article/details/2476224
http://blog.sina.com.cn/s/blog_3d7bed6501000c85.html
列表查询组件代码, 简化拼接条件SQL语句的麻烦
http://www.cnblogs.com/wuhuacong/archive/2007/11/19/964100.html
多条件搜索分页的实现
http://www.cnblogs.com/dedeyi/archive/2013/03/13/2957790.html