/// <summary>
/// 根据RowNum获取某一分页的内容
/// </summary>
/// <param name="connectionString">数据库连接字符串</param>
/// <param name="sql">原始SQL语句</param>
/// <param name="currentPageIndex">当前页码</param>
/// <param name="pageSize">每页记录条数</param>
/// <param name="recordCount">记录总数</param>
/// <param name="cmdParms">参数数组</param>
/// <returns>分页后的DataTable数据集</returns>
public static DataTable GetPagerDataByRowNum(string connectionString, string sql, int currentPageIndex, int pageSize, out int recordCount, params OracleParameter[] cmdParms)
{
recordCount = 0;
if (currentPageIndex <= 0)
{
currentPageIndex = 1;
}
if (pageSize <= 0)
{
pageSize = 10;
}
int recordStartIndex = (currentPageIndex - 1) * pageSize + 1;
int recordEndIndex = currentPageIndex * pageSize;
string newSql = string.Format("select * from (select temptb.*,rownum myrowno from ({0}) temptb where rownum<=:recordEndIndex) where myrowno>=:recordStartIndex", sql);
List <OracleParameter> cmdParmList = new List <OracleParameter>();
if (cmdParms != null && cmdParms.Length > 0)
{
foreach (OracleParameter parm in cmdParms)
{
cmdParmList.Add(parm);
}
}
cmdParmList.Add(DbHelperOracle.AddInParameter("recordEndIndex", recordEndIndex));
cmdParmList.Add(DbHelperOracle.AddInParameter("recordStartIndex", recordStartIndex));
DataTable dt = DbHelperOracle.ExecuteDataTable(connectionString, newSql, cmdParmList.ToArray());
recordCount = GetRecordCount(connectionString, sql, cmdParms);
return(dt);
}
/// <summary>
/// 根据SQL语句获得某一页的内容(RowNumeber)
/// </summary>
/// <param name="conn">数据库连接</param>
/// <param name="sql">原始SQL语句</param>
/// <param name="overExpress">over表达式(比如：ID Desc,)</param>
/// <param name="currentPageIndex">当前页码</param>
/// <param name="pageSize">每页记录条数</param>
/// <param name="cmdParms">参数数组</param>
/// <returns>分页后的DataTable数据集</returns>
public static DataTable GetPagerDataByRowNumber(OracleConnection conn, string sql, string overExpress, int currentPageIndex, int pageSize, params OracleParameter[] cmdParms)
{
if (currentPageIndex <= 0)
{
currentPageIndex = 1;
}
if (pageSize <= 0)
{
pageSize = 10;
}
int recordStartIndex = (currentPageIndex - 1) * pageSize + 1;
int recordEndIndex = currentPageIndex * pageSize;
// 得到from所在的位置
int fromIndex = sql.LastIndexOf(" from ", StringComparison.OrdinalIgnoreCase);
// 得到查询的字段
string fields = sql.Substring(7, fromIndex - 7);
// 得到from后面的语句
string from = sql.Substring(fromIndex);
// 拼凑要执行的SQL语句
string newSql = string.Format("select * from (select {0},row_number() over({1}) myrowno {2}) where myrowno between :recordStartIndex and :recordEndIndex", fields, overExpress, from);
List <OracleParameter> cmdParmList = new List <OracleParameter>();
if (cmdParms != null && cmdParms.Length > 0)
{
foreach (OracleParameter parm in cmdParms)
{
cmdParmList.Add(parm);
}
}
cmdParmList.Add(DbHelperOracle.AddInParameter("recordEndIndex", recordEndIndex));
cmdParmList.Add(DbHelperOracle.AddInParameter("recordStartIndex", recordStartIndex));
DataTable dt = DbHelperOracle.ExecuteDataTable(conn, newSql, cmdParmList.ToArray());
return(dt);
}
/// <summary>
/// 根据SQL语句获得相应的记录数
/// </summary>
/// <param name="conn">数据库连接</param>
/// <param name="sql">原始SQL语句</param>
/// <param name="cmdParms">参数数组</param>
/// <returns>记录数</returns>
public static int GetRecordCount(OracleConnection conn, string sql, params OracleParameter[] cmdParms)
{
string newSql = string.Format("select count(*) from ({0}) temp001", sql);
object count = DbHelperOracle.ExecuteScalar(conn, newSql, cmdParms);
if (count == null || count == DBNull.Value)
{
return(0);
}
else
{
return(Convert.ToInt32(count));
}
}
