一個(gè)數(shù)據(jù)庫(kù)操作類的實(shí)例（一.Command類部分）
2024-07-21 02:23:46
供稿：網(wǎng)友
using system;
namespace com.joybase.db
{
/// <summary>
/// 數(shù)據(jù)庫(kù)操作類，通過(guò)這一個(gè)類的對(duì)外接口，可以獲得以下特性：
/// 1.不必區(qū)分?jǐn)?shù)據(jù)庫(kù)類型，而去考慮是使用system.data.sqlclient實(shí)現(xiàn)，或者使用system.data.oledb來(lái)實(shí)現(xiàn);
/// 2.可以將sql語(yǔ)句進(jìn)行模式化，比如輸入“select * from tablename where username=? order by ? desc"，然后再用建模語(yǔ)句將該語(yǔ)句保持完整;
/// 3.數(shù)據(jù)庫(kù)連接實(shí)現(xiàn)connection pool（該特性是建立在ado.net的基礎(chǔ)上的）
/// 4.支持sql語(yǔ)句的datareader輸出、無(wú)輸出或者dataset輸出;
/// 5.支持ado.net事務(wù)級(jí)處理;
/// 6.支持存儲(chǔ)過(guò)程的輸入及輸出;
/// </summary>
public class command
{
//最終的sql語(yǔ)句;
private system.text.stringbuilder m_sql;
//中間過(guò)程的sql語(yǔ)句數(shù)組
private string[] m_sqlarr;
//替代字符串的數(shù)組;
private string[] m_replacetext;
//替代字符串的個(gè)數(shù);
private int m_count;
//連接類型;
private system.data.commandtype m_commandtype;
//在配置文件中用來(lái)配置數(shù)據(jù)庫(kù)連接字符串的標(biāo)簽;
private string m_connstringsetname;
/// <summary>
/// 構(gòu)造方法
/// </summary>
/// <param name="p_sql">模式sql語(yǔ)句</param>
public command(string p_sql)
{
if(p_sql==null) throw new exception("error value");
if(p_sql.trim()=="") throw new exception("error value");
this.m_sql=new system.text.stringbuilder();
m_sqlarr=p_sql.split('?');
m_count=m_sqlarr.length;
m_replacetext=new string[m_count-1];
m_connstringsetname="";
this.m_commandtype=system.data.commandtype.text;
}
/// <summary>
/// 在配置文件中用來(lái)配置數(shù)據(jù)庫(kù)連接字符串的標(biāo)簽，如果不設(shè)置，則將采用“database.connectionstring”作為連接字符串使用
/// </summary>
public string connstringsetname
{
set
{
this.m_connstringsetname=value;
}
}
/// <summary>
/// 所執(zhí)行命令的類型，即是存儲(chǔ)過(guò)程還是普通sql語(yǔ)句;
/// </summary>
public system.data.commandtype commandtype
{
set
{
this.m_commandtype=value;
}
}
/// <summary>
/// 以指定的字符串替代在p_loaction位置上的“?”;
/// </summary>
/// <param name="p_location">位置索引</param>
/// <param name="p_instring">欲替代的字符串</param>
public void setstring(int p_location,string p_instring)
{
if(p_instring==null) throw new exception("error value");
if(p_instring.trim()==null) throw new exception("error value");
m_replacetext[p_location-1]="'"+p_instring.trim()+"'";
}
/// <summary>
/// 以指定的整數(shù)類型，替代在p_location位置上的"?"
/// </summary>
/// <param name="p_location">位置索引</param>
/// <param name="p_inint">欲替代的整數(shù)</param>
public void setint(int p_location,int p_inint)
{
m_replacetext[p_location-1]=p_inint.tostring();
}
/// <summary>
/// 以指定的長(zhǎng)整數(shù)類型，替代在p_location位置上的"?"
/// </summary>
/// <param name="p_location">位置索引</param>
/// <param name="p_inlong">欲替代的長(zhǎng)整數(shù)</param>
public void setlong(int p_location,int p_inlong)
{
m_replacetext[p_location-1]=p_inlong.tostring();
}
/// <summary>
/// 以指定的時(shí)間，替代在p_location位置上的"?"
/// </summary>
/// <param name="p_location">位置索引</param>
/// <param name="p_indatetime">欲替代的時(shí)間</param>
public void setdatetime(int p_location,system.datetime p_indatetime)
{
m_replacetext[p_location-1]=p_indatetime.tostring();
}
/// <summary>
/// 以系統(tǒng)時(shí)間替代在p_location位置的"?"
/// </summary>
/// <param name="p_location">位置索引</param>
/// <param name="p_onlydate">如果為true，則僅替代到日期，如果為false，則替代到時(shí)間</param>
public void setdatetime(int p_location,bool p_onlydate)
{
if(p_onlydate)
m_replacetext[p_location-1]=system.datetime.now.date.tostring();
else
m_replacetext[p_location-1]=system.datetime.now.tostring();
}
private string joinsqlstring()
{
for(int i=0;i<m_count;i++)
{
if(i!=0) this.m_sql.append(m_replacetext[i-1]);
this.m_sql.append(m_sqlarr[i]);
}
return this.m_sql.tostring();
}
/// <summary>
/// 執(zhí)行命令并且返回system.data.idatareader結(jié)果的結(jié)果集
/// </summary>
/// <returns></returns>
public system.data.idatareader result()
{
system.data.idatareader result=null;
try
{
system.data.idbcommand command=provider.getconn(m_connstringsetname).createcommand();
command.commandtext=this.joinsqlstring();
command.commandtype=this.m_commandtype;
command.connection.close();
command.connection.open();
command.prepare();
//if(provider.getconn(m_connstringsetname).state==system.data.connectionstate.closed)
//provider.getconn(m_connstringsetname).open();
result=command.executereader();
//command.connection.close();
//provider.getconn().close();
}
catch
{
throw new exception("error at execute db command");
}
return result;
}
/// <summary>
/// 無(wú)結(jié)果執(zhí)行命令
/// </summary>
public void executenoresult()
{
try
{
system.data.idbcommand command=provider.getconn(m_connstringsetname).createcommand();
command.commandtext=this.joinsqlstring();
command.commandtype=this.m_commandtype;
command.connection.close();
command.connection.open();
//if(provider.getconn(m_connstringsetname).state==system.data.connectionstate.closed)
//provider.getconn(m_connstringsetname).open();
command.executenonquery();
}
catch
{
throw new exception("error at execute db command");
}
}
}
}
