using
System;
using
System.Collections;
using
System.Collections.Generic;
using
System.Text;
using
System.Data;
using
System.Data.Common;
using
System.Data.OleDb;
namespace
Common
{
/// <summary>
/// OleDb 书库访问类
/// </summary>
public
static
class
OleDbHelper
{
/// <summary>
/// Access 的数据库连接字符串格式.
/// </summary>
public
const
string
ACCESS_CONNECTIONSTRING_TEMPLATE =
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};"
;
private
static
Hashtable parmCache = Hashtable.Synchronized(
new
Hashtable());
/// <summary>
/// 针对 System.Data.OleDb.OleDbCommand.Connection 执行 SQL 语句并返回受影响的行数.
/// </summary>
/// <param name="connString"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
int
ExecuteNonQuery(
string
connString, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
using
(OleDbConnection conn =
new
OleDbConnection(connString))
{
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.Open);
int
val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return
val;
}
}
/// <summary>
/// 针对 System.Data.OleDb.OleDbCommand.Connection 执行 SQL 语句并返回受影响的行数.
/// </summary>
/// <param name="conn"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
int
ExecuteNonQuery(OleDbConnection conn, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.AutoDetection);
int
val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return
val;
}
/// <summary>
/// 针对 System.Data.OleDb.OleDbCommand.Connection 执行 SQL 语句并返回受影响的行数.
/// </summary>
/// <param name="trans"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
int
ExecuteNonQuery(OleDbTransaction trans, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, cmdParms, ConnectionActionType.None);
int
val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return
val;
}
/// <summary>
/// 将 System.Data.OleDb.OleDbCommand.CommandText 发送到 System.Data.OleDb.OleDbCommand.Connection 并生成一个 System.Data.OleDb.OleDbDataReader.
/// </summary>
/// <param name="connString"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
OleDbDataReader ExecuteReader(
string
connString, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
OleDbConnection conn =
new
OleDbConnection(connString);
try
{
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.Open);
OleDbDataReader rdr = cmd.ExecuteReader();
cmd.Parameters.Clear();
return
rdr;
}
catch
{
conn.Close();
throw
;
}
}
/// <summary>
/// 将 System.Data.OleDb.OleDbCommand.CommandText 发送到 System.Data.OleDb.OleDbCommand.Connection 并生成一个 System.Data.OleDb.OleDbDataReader.
/// </summary>
/// <param name="conn"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
OleDbDataReader ExecuteReader(OleDbConnection conn, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
try
{
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.AutoDetection);
OleDbDataReader rdr = cmd.ExecuteReader();
cmd.Parameters.Clear();
return
rdr;
}
catch
{
conn.Close();
throw
;
}
}
/// <summary>
/// 执行查询,并返回查询所返回的结果集中第一行的第一列。忽略其他列或行.
/// </summary>
/// <param name="connString"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
object
ExecuteScalar(
string
connString, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
using
(OleDbConnection conn =
new
OleDbConnection(connString))
{
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.Open);
object
val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return
val;
}
}
/// <summary>
/// 执行查询,并返回查询所返回的结果集中第一行的第一列。忽略其他列或行.
/// </summary>
/// <param name="conn"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
object
ExecuteScalar(OleDbConnection conn, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.AutoDetection);
object
val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return
val;
}
/// <summary>
/// 执行查询,并返回查询所返回的结果数据集.
/// </summary>
/// <param name="connString"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
DataSet ExecuteDataset(
string
connString, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
using
(OleDbConnection conn =
new
OleDbConnection(connString))
{
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.Open);
OleDbDataAdapter da =
new
OleDbDataAdapter(cmd);
DataSet ds =
new
DataSet();
da.Fill(ds);
cmd.Parameters.Clear();
return
ds;
}
}
/// <summary>
/// 执行查询,并返回查询所返回的结果数据集.
/// </summary>
/// <param name="conn"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public
static
DataSet ExecuteDataset(OleDbConnection conn, CommandType cmdType,
string
cmdText,
params
OleDbParameter[] cmdParms)
{
OleDbCommand cmd =
new
OleDbCommand();
PrepareCommand(cmd, conn,
null
, cmdType, cmdText, cmdParms, ConnectionActionType.AutoDetection);
OleDbDataAdapter da =
new
OleDbDataAdapter(cmd);
DataSet ds =
new
DataSet();
da.Fill(ds);
cmd.Parameters.Clear();
return
ds;
}
/// <summary>
/// 缓存查询的 OleDb 参数对象.
/// </summary>
/// <param name="cacheKey"></param>
/// <param name="cmdParms"></param>
public
static
void
CacheParameters(
string
cacheKey,
params
OleDbParameter[] cmdParms)
{
parmCache[cacheKey] = cmdParms;
}
/// <summary>
/// 从缓存获取指定的参数对象数组.
/// </summary>
/// <param name="cacheKey"></param>
/// <returns></returns>
public
static
OleDbParameter[] GetCachedParameters(
string
cacheKey)
{
OleDbParameter[] cachedParms = (OleDbParameter[])parmCache[cacheKey];
if
(cachedParms ==
null
)
return
null
;
OleDbParameter[] clonedParms =
new
OleDbParameter[cachedParms.Length];
for
(
int
i = 0, j = cachedParms.Length; i < j; i++)
clonedParms[i] = (OleDbParameter)((ICloneable)cachedParms[i]).Clone();
return
clonedParms;
}
/// <summary>
/// 准备命令对象.
/// </summary>
/// <param name="cmd"></param>
/// <param name="conn"></param>
/// <param name="trans"></param>
/// <param name="cmdType"></param>
/// <param name="cmdText"></param>
/// <param name="cmdParms"></param>
/// <param name="connActionType"></param>
private
static
void
PrepareCommand(OleDbCommand cmd, OleDbConnection conn, OleDbTransaction trans, CommandType cmdType,
string
cmdText, OleDbParameter[] cmdParms, ConnectionActionType connActionType)
{
if
(connActionType == ConnectionActionType.Open)
{
conn.Open();
}
else
{
if
(conn.State != ConnectionState.Open)
conn.Open();
}
cmd.Connection = conn;
cmd.CommandText = cmdText;
if
(trans !=
null
)
cmd.Transaction = trans;
cmd.CommandType = cmdType;
if
(cmdParms !=
null
)
{
foreach
(OleDbParameter parm
in
cmdParms)
cmd.Parameters.Add(parm);
}
}
/// <summary>
/// 统一分页显示数据记录
/// </summary>
/// <param name="connString">数据库连接字符串</param>
/// <param name="pageIndex">当前页码</param>
/// <param name="pageSize">每页显示的条数</param>
/// <param name="fileds">显示的字段</param>
/// <param name="table">查询的表格</param>
/// <param name="where">查询的条件</param>
/// <param name="order">排序的规则</param>
/// <param name="pageCount">out:总页数</param>
/// <param name="recordCount">out:总条数</param>
/// <param name="id">表的主键</param>
/// <returns>返回DataTable集合</returns>
public
static
DataTable ExecutePager(
string
connString,
int
pageIndex,
int
pageSize,
string
fileds,
string
table,
string
where,
string
order,
out
int
pageCount,
out
int
recordCount,
string
id)
{
if
(pageIndex < 1) pageIndex = 1;
if
(pageSize < 1) pageSize = 10;
if
(
string
.IsNullOrEmpty(fileds)) fileds =
"*"
;
if
(
string
.IsNullOrEmpty(order)) order =
"ID desc"
;
using
(OleDbConnection conn =
new
OleDbConnection(connString))
{
string
myVw =
string
.Format(
" {0} "
, table);
string
sqlText =
string
.Format(
" select count(0) as recordCount from {0} {1}"
, myVw, where);
OleDbCommand cmdCount =
new
OleDbCommand(sqlText, conn);
if
(conn.State == ConnectionState.Closed)
conn.Open();
recordCount = Convert.ToInt32(cmdCount.ExecuteScalar());
if
((recordCount % pageSize) > 0)
pageCount = recordCount / pageSize + 1;
else
pageCount = recordCount / pageSize;
OleDbCommand cmdRecord;
if
(pageIndex == 1)
{
cmdRecord =
new
OleDbCommand(
string
.Format(
"select top {0} {1} from {2} {3} order by {4} "
, pageSize, fileds, myVw, where, order), conn);
}
else
if
(pageIndex > pageCount)
{
cmdRecord =
new
OleDbCommand(
string
.Format(
"select top {0} {1} from {2} {3} order by {4} "
, pageSize, fileds, myVw,
"where 1=2"
, order), conn);
}
else
{
int
pageLowerBound = pageSize * pageIndex;
int
pageUpperBound = pageLowerBound - pageSize;
string
recordIDs = RecordID(
string
.Format(
"select top {0} {1} from {2} {3} order by {4} "
, pageLowerBound, id, myVw, where, order), pageUpperBound, conn);
cmdRecord =
new
OleDbCommand(
string
.Format(
"select {0} from {1} where {4} in ({2}) order by {3} "
, fileds, myVw, recordIDs, order, id), conn);
}
OleDbDataAdapter dataAdapter =
new
OleDbDataAdapter(cmdRecord);
DataTable dt =
new
DataTable();
dataAdapter.Fill(dt);
return
dt;
}
}
private
static
string
RecordID(
string
query,
int
passCount, OleDbConnection conn)
{
OleDbCommand cmd =
new
OleDbCommand(query, conn);
string
result =
string
.Empty;
using
(IDataReader dr = cmd.ExecuteReader())
{
while
(dr.Read())
{
if
(passCount < 1)
{
result +=
","
+ dr.GetInt32(0);
}
passCount--;
}
}
return
result.Substring(1);
}
/// <summary>
/// 连接操作类型枚举.
/// </summary>
enum
ConnectionActionType
{
None = 0,
AutoDetection = 1,
Open = 2
}
}
}