c#學習之-c#通過sql存儲過程實現分頁
分頁的重要性不言而喻，本文將相信的講解c#通過sql進行分頁的實現（三層）
數據庫表如下
現在編寫sql分頁通用存儲過程
if exists (select 1
from sysobjects
where [name]='proc_CommonPage'
and [type]='p')
drop proc proc_CommonPage--檢查是否存在該存儲過程 如果存在刪除
go
create proc proc_CommonPage--創建存儲過程( @pageSize int,--分頁大小（每一頁多少）
@pageIndex int,--分頁索引（頁數）
@tablename varchar(50),--表名
@prikey varchar(20),--查詢關鍵字（以什麼排序）
@condtional varchar(2000),--查詢條件
@sort varchar(4),--排序
@pageCount int out --總頁數
)
as
--構建查詢的sql語句
declare @sql nvarchar(1000);--查詢的sql
declare @recordCount int,--數據總數
@startIndex int,--分頁的啓示行
@endIndex int--分頁的結束行
set @sql='select @recordCount=count(*) from '+@tablename+' where 1=1 ';
if @condtional is not null and @condtional<> N''--查詢條件不爲空 也不爲空格
begin
set @sql=@sql+@condtional
end
--print @sql
exec sp_executesql @sql,N'@recordCount int out',@recordCount out;--執行系統sp_executesql存儲過程print @recordCount
--計算最大的分頁數--
set @pageCount = CEILING(@recordcount*1.0/@pagesize);--最大的分頁數 進一法取值
if @pageindex > @pageCount --如果分頁的索引大於最大的索引
begin
set @pageindex = @pageCount;
end
--構建分頁的查詢的起始行和結束行
set @startIndex = (@pageindex-1)*@pagesize +1;--計算起始行
set @endIndex = @pageindex *@pagesize
--構建分頁的sql
set @sql =''
print @pagecount
set @sql = 'Select row_number() over (order by '+@prikey+ ' ' +@sort+') as rowid,* from '+@tablename+' where 1=1';
if @condtional is not null and @condtional <> N'' --如果查詢條件不爲空
begin
set @sql = @sql+ @condtional;
end
set @sql = 'Select * From ('+@sql+') as tc where tc.rowid between '+convert(varchar(5),@startIndex)+' and '+convert(varchar(5),@endIndex)+'';
exec (@sql)
go在這個存儲過程中有2個地方需要注意
第一 sp_executesql
執行可以多次重複使用或動態生成的 Transact-SQL 語句或批處理。Transact-SQL 語句或批處理可以包含嵌入參數。
(個人理解)主要可以執行一個sql語句 並且可以傳出參數 用來作爲下一條語句的條件 它的參數必須是Unicode字符格式
第二 row_number()
select row_number() over (order by empid asc) as rowid 像表中插入一列帶有順序的id
UI層
EmployedBll eb = new EmployedBll(); int pageSize = 6; int pageIndex = 1; int pageCount = 0; string pageConditiona = "";
List<TbEmployed> list = eb.GetListByPage(pageSize, pageIndex, pageConditiona, pageSort, out pageCount);
this.gridControl1.DataSource = list; BLL層
private string pageSort = "asc";
public List<TbEmployed> GetListByPage(int PageSize, int pageIndex, string seletstr,string pageSort, out int pageCount)
{
return ed.GetListByPage(PageSize, pageIndex, seletstr,pageSort, out pageCount);
}
DAL層
public List<TbEmployed> GetListByPage(int pageSize, int pageIndex, string seletcondtional,string pageSort,out int pagecount)
{
#region MyRegion
SqlParameter parIndex = new SqlParameter("@pageIndex", SqlDbType.Int);
parIndex.Value = pageIndex;
SqlParameter parSize = new SqlParameter("@PageSize", SqlDbType.Int);
parSize.Value = pageSize;
SqlParameter parTname = new SqlParameter("@tablename", SqlDbType.VarChar);
parTname.Value = "tb_Employed";
SqlParameter parPrikey = new SqlParameter("@prikey", SqlDbType.VarChar);
parPrikey.Value = "empid";
SqlParameter parSort = new SqlParameter("@pageSort", SqlDbType.VarChar);
parSort.Value = pageSort;SqlParameter parCondtional = new SqlParameter("@condtional", SqlDbType.VarChar);
parCondtional.Value =seletcondtional;
SqlParameter parCount = new SqlParameter("@pagecount", SqlDbType.Int);
parCount.Direction = ParameterDirection.Output;//傳出參數 Direction
SqlParameter[] pars = { parSize, parIndex, parTname, parPrikey, parCondtional,parSort, parCount };
string sql = " exec proc_CommonPage @pageSize,@pageIndex,@tablename,@prikey,@condtional,@pageSort, @pagecount out";
DataTable dt = _sqlhelper.GetDataSet(sql, pars).Tables[0];
// DataTable dt = _sqlhelper.GetDataTable(sql, pars);
pagecount = (int)parCount.Value;//把結構賦值給傳出參數Pagecount
List<TbEmployed> list = GetListModel(dt);
#endregion
#region MyRegion
//string tablename = "tb_Employed";
//string prikey = "empid";
//string condtional = "";
//DataTable dt =
// _sqlhelper.GetDataSet(
// @"exec proc_CommonPage @pageIndex,@PageSize,@tablename,@prikey,@condtional,@pageCount out",
// new SqlParameter("@pageIndex", pageIndex),
// new SqlParameter("@PageSize", PageSize),
// new SqlParameter("@tablename", tablename),
// new SqlParameter("@prikey", prikey),
// new SqlParameter("@condtional", condtional),
// new SqlParameter("@pageCount", pageCount)).Tables[0];
//pageCount = (int)parCount.Value;//把結構賦值給傳出參數Pagecount
//List<TbEmployed> list = GetListModel(dt);
#endregion
return list;
<pre class="csharp" name="code"> private List<TbEmployed> GetListModel(DataTable dt)
{
List<TbEmployed> list = new List<TbEmployed>();
foreach (DataRow dr in dt.Rows)
{
TbEmployed te = new TbEmployed();
te.empid = (int) dr["empid"];
te.empname = dr["empname"].ToString();
te.roleid = (int) dr["roleid"];
te.empsex = dr["empsex"].ToString();
te.empage = (int)dr["empage"];
te.emplogin = dr["emplogin"].ToString();
te.empwd = dr["empwd"].ToString();
list.Add(te);
}
return list;
}AbstractSqlHelper
public SqlCommand GetCommand(string sql, params SqlParameter[] pars)
{
GetConnection();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = sql;
if (pars != null)
{
cmd.Parameters.AddRange(pars);
}
return cmd;
} public void GetConnection()
{ //private static string conStr = ConfigurationManager.ConnectionStrings["sqlstr"].ConnectionString;
string strCon = ConfigurationManager.ConnectionStrings["sqlstr"].ConnectionString;
conn = new SqlConnection(strCon);
conn.Open();
if (conn.State!=ConnectionState.Open)
{
conn.Close();
conn.Dispose();
}
}
public SqlCommand GetCommand(string sql, params SqlParameter[] pars)
{
GetConnection();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = sql;
if (pars != null)
{
cmd.Parameters.AddRange(pars);
}
return cmd;
}
SqlHelper
public override DataSet GetDataSet(string sql, params SqlParameter[] parameters)
{
SqlCommand cmd = GetCommand(sql, parameters);
SqlDataAdapter sda = new SqlDataAdapter(cmd);
DataSet dataset = new DataSet();
sda.Fill(dataset);
return dataset;
}
以上是實習分頁的全部代碼
model省略了的
表名 關鍵字也可以通過參數傳入
代碼間調用就是普通的調用 數據連接的打開在抽象類中
連接字符串在配置文件中
以winfrom 爲教材
希望大家批評指教
