📄 appbuilder中进行直接odbc api数据库调用访问的基本方法.htm
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AppBuilder中进行直接ODBC API数据库调用访问的基本方法!
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AppBuilder中进行直接ODBC API数据库调用访问的基本方法!
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<br><br>作者：张修勇 appbuilder的网址：http://www.ucancode.com<br><br>第一章：如何为你的开发系统配置dsn：<br><br>（一）、打开windows的控制面板。选择odbc data sources图标，双击打开此图标内容，此时出现odbc data source administrator对话框。<br><br> <br><br>（2）、在对话框中选择user dsn然后你可以选择<添加>按钮来新增一个dsn.<br><br> <br><br>第二章：如何利用odbc api在vc下面直接编写基于数据库的程序：<br><br>odbc数据库编程<br>一、 一般步骤： <br><br>分配环境 <br><br>应用系统在调用任何odbc函数之前，首先必须初始化odbc，并建立一个环境。<br>odbc用该环境监视应用系统已经建立的数据库连接。每个应用系统只建立一个<br>环境是很有必要的，因为不管有多少连接都可以在一个环境中建立。完成这一分<br>配过程的odbc函数sqlallocenv在下一小节描述。<br><br>sqlallocenv<br>sqlallocenv为环境句柄分配内存，并初始化应用系统使用的odbc调用层接口。<br>应用系统在调用任何其他odbc函数之前必须调用sqlallocenv。<br>以下是sqlallocenv的语法：<br>retcode sqlallocenv(phenv)<br>sqlallocenv的参数如下表所示，其返回码是sql-error。因为调用sqlerror<br>时无有效句柄，所以该函数没有sqlstate返回码； <br>//分配环境句柄<br>sqlreturn m_retcode;<br>if( m_henv != sql_null_henv )<br>return false;<br>if (sql_success == (m_retcode = sqlallocenv( &m_henv )))<br>{<br>//创建新的dsn<br>createdsn(ids_home_dsnname,ids_home_dbfilename);<br>//分配连接句柄<br>if (sql_success == (m_retcode = sqlallocconnect( m_henv, &m_hdbc )))<br>{<br>// 连接数据源<br>if (sql_success == (m_retcode = sqlconnect( m_hdbc, (uchar *)((lpctstr)m_strdsn), sql_nts, null, 0, null, 0 )))<br>{<br>m_bconnected = true;<br>}<br>}<br>}<br>分配连接句柄<br><br>就象应用系统的环境由环境句柄代表一样，连接句柄代表应用系统与数据源<br>之间的连接。对于应用系统所要连接的每一个数据源而言，都必须分配一个连接<br>句柄。例如，如果需要同时与dbase和btrieve的数据源连接，必须分配两个连接<br>句柄。下一小节描述函数sqlallocconnect.<br><br>sqlallocconnect在henv标识的环境里为连接句柄分配内存。以下是<br>sqlallocconnect的语法：<br>retcode sqlallocconnect(henv,phdbc)<br>sqlallocconnect 的参数如下表所示，其返回码是：<br>sql-success<br>sql-success-with-info<br>sql-error<br>sql-invalid-handle<br>sqlstate的返回码是：<br>01000 s1000 s1001 s1009<br>利用核心函数与数据源连接<br><br>尽管有很多odbc函数可以建立连接，但在核心api层却只有一种，即函数<br>sqlconnect。它提供简单、有效的方法与数据源的连接。所有驱动程序都支持<br>sqlconnect，所以它是最具有互用性的解决方案。下面是sqlconnect的描述。<br><br>sqlconnect加载一个数据库驱动程序，并建立一个与数据源的连接。该连接<br>句柄确定所有连接信息（包括它的状态，事务状态和错误信息）的存储位置。<br><br>sqlconnect的语法如下：<br>retcode sqlconnect(hdbc,szdsn,cbdsn,szuid,cbuid,szauthstr,cbauthatr)<br><br>sqlconnectde的返回码是：<br>sql-success<br>sql-success-with-info<br>sql-error<br>sql-invalid-number<br><br><br>与数据源断开<br><br>应用系统一旦使用完成一个数据源连接，便应与之断开。连接是十分昂贵<br>的资源，因为很多dbms对同时连接的每一个许可人员或用户都是收费的。当<br>连接完成时，应当把它返回，以便其它用户能注册进入该系统。下面描述的odbc<br>函数sqldisconnect处理这一操作过程。<br><br>sqldisconnect关闭与指定的连接句柄相关的数据源连接。sqldisconnect<br>的语法如下：<br>retcodesqldisconnect（hdbc）<br>sqldisconnect的返回码是：<br>sql-success<br>sql-success-with-info<br>sql-error<br>sql-invalid-handle <br><br>如果数据源连接成功的话，就可以继续下一步；<br>cstring strsqlstring;<br>retcode returncode;<br>sqlhstmthstmt;<br>if (sql_success != sqlallochandle(sql_handle_stmt,theapp.m_hdbc,&hstmt))<br>return;<br>strsqlstring.format(<br>"select "<br>"nid,"<br>"ariqi,"<br>"njine,"<br>"ashuoming,"<br>"alaiyuan,"<br>"acunzhe,"<br>"ayongtu,"<br>"axiaofei,"<br>"abeizhu"<br>" from hhzhichu "<br>" where nid=%u",<br>nid);<br>if (sql_success == (returncode = sqlexecdirect(hstmt,(uchar*)((lpctstr)strsqlstring),sql_nts)))<br>{<br>sqlbindcol(hstmt,1,sql_c_slong,&dbdata.m_nid,0,&cb);<br>sqlbindcol(hstmt,2,sql_c_timestamp,&dbdata.m_ariqi,0,&cb);<br>sqlbindcol(hstmt,3,sql_c_double,&dbdata.m_njine,0,&cb);<br>sqlbindcol(hstmt,4,sql_c_char,dbdata.m_ashuoming,hhzhichu_ashuoming_size,&cb);<br>sqlbindcol(hstmt,5,sql_c_char,dbdata.m_alaiyuan,hhzhichu_alaiyuan_size,&cb);<br>sqlbindcol(hstmt,6,sql_c_char,dbdata.m_acunzhe,hhzhichu_acunzhe_size,&cb);<br>sqlbindcol(hstmt,7,sql_c_char,dbdata.m_ayongtu,hhzhichu_ayongtu_size,&cb);<br>sqlbindcol(hstmt,8,sql_c_char,dbdata.m_axiaofei,hhzhichu_axiaofei_size,&cb);<br>sqlbindcol(hstmt,9,sql_c_char,dbdata.m_abeizhu,hhzhichu_abeizhu_size,&cb);<br>if (sql_success == (returncode = sqlfetch(hstmt)))<br>{<br>//读数据成功，可一对数据进行处理了。<br>}<br>}<br>::sqlfreehandle(sql_handle_stmt,hstmt);<br><br><br>程序完了后要关闭数据库，<br>//断开连接<br>if (m_bconnected)<br>{<br>sqldisconnect(m_hdbc);<br>sqlfreehandle(sql_handle_dbc,m_hdbc);<br>m_hdbc = null;<br>}<br>//删除dsn<br>if (founddsnname(ids_home_dsnname))<br>deletedsn(ids_home_dsnname);<br>//删除环境句柄<br>if (m_henv)<br>{<br>sqlfreehandle(sql_handle_env,m_henv);<br>m_henv = null;<br>}<br><br>二、 针对数据库的操作<br>以下的方法只对access数据库有效，<br>1、 生成数据库<br>cstring strfilename="c:\1.mdb";<br>cstring strdriver;<br>char szfilename[100+_max_path];<br>strdriver = "microsoft access driver (*.mdb)\0";<br>sprintf(szfilename,"create_db=%s general\0\0",strfilename);<br>sqlconfigdatasource(null,odbc_add_dsn,strdriver,szfilename);<br>2、 压缩数据库<br>bool superdatabase::compaction(cstring strsourname, cstring strdestname)<br>{<br>if (strsourname.isempty())<br>return false;<br>if (strdestname.isempty())<br>strdestname = strsourname;<br>char szcommand[100+_max_path];<br>int j;<br>cstring strdriver;<br>strdriver = "microsoft access driver (*.mdb)\0";<br>j = sprintf(szcommand,"compact_db=%s %s general\0\0",strsourname,strdestname);<br>return sqlconfigdatasource(null,odbc_add_dsn,strdriver,szcommand);<br>}<br>3、 取得数据库的名称：<br>如果已经打开了一个数据源，可以通过数据源来取得当前的数据库的名称；<br>cstring superdatabase::getdatabasename()<br>{<br>assert(m_hdbc != sql_null_hdbc);<br>char szname[max_tname_len];<br>sword nresult;<br>sqlgetinfo(m_hdbc, sql_database_name,<br>szname, max_tname_len, &nresult);<br>return szname;<br>}<br><br>三、 针对数据源的操作：<br>1、 增加数据源<br>bool superdatabase::createdsn(cstring strdriver, cstring strfilename,cstring strdsn, cstring struserid, cstring strpwd)<br>{<br>char szattr[100+_max_path];<br>int j;<br>if (strdriver.isempty())<br>strdriver = "microsoft access driver (*.mdb)\0";<br>j = sprintf(szattr,"dsn=%s\0",strdsn);<br>j++;<br>j = sprintf(szattr+j,"dbq=%s\0\0 ",strfilename);<br>return sqlconfigdatasource(null,odbc_add_dsn,strdriver,szattr);<br>}<br>2、 删除数据源<br>void superdatabase::removedsn(cstring strdsn)<br>{<br>char szdsn[255];<br>sprintf(szdsn,"dsn=%s\0\0",strdsn);<br>bool bissuccess = sqlconfigdatasource(null,odbc_remove_dsn,"microsoft access driver (*.mdb)\0",szdsn);<br>}<br>3、 取得系统已有得dsn<br>sword ndatasourcenamelength; //dsn str length<br>sword nsourcedescriptionlength; //driver description str length<br>char szsourcedescription[maxbuflen+1]; //driver description string<br>sqlreturn nresult; //return code<br>sword ndirection=sql_fetch_first;<br>if ((nresult = sqldatasources(m_henv, ndirection, (uchar *)((lpctstr)strdatasourcename), maxbuflen, &ndatasourcenamelength, (uchar *)szsourcedescription, maxbuflen, &nsourcedescriptionlength)) != sql_no_data && nresult != sql_error)<br>{<br>ndirection=sql_fetch_next;<br>// szsourcedescription为dsn 的描述，可以在这里取来用；<br>}<br><br>四、 针对表的操作：<br>1、 取得表名：<br>void superdatabase::gettable(cstringlist &tablelist)<br>{<br>assert(m_bisconnect);<br>if (!m_bisconnect)<br>return;<br>sqlhstmt hstmt = null;<br>if (sql_success == ::sqlallochandle(sql_handle_stmt, m_hdbc, &hstmt))<br>{<br>if (sql_success == ::sqltables(hstmt, null, 0, null, 0,<br>null, 0, null, 0))<br>{<br>sdword cb;<br>char sztable[255];<br>char sztabletype[255];<br>::sqlbindcol(hstmt, 3, sql_c_char, sztable, 255, &cb);<br>::sqlbindcol(hstmt, 4, sql_c_char, sztabletype, 255, &cb);<br>while (sql_success == ::sqlfetch(hstmt))<br>{<br>if (0 == strcmp(sztabletype, "table"))//table表示表，view表示查询<br>{<br>tablelist.addtail(sztable);<br>}<br>}<br>}<br>}<br>::sqlfreehandle(sql_handle_stmt, hstmt);<br>hstmt = null;<br>}<br>2、 创建表：可以用sql语句生成表，使用的命令为："create table"：<br>create table table (field1 type [(size)] [not null] [index1] [, field2 type [(size)] [not null] [index2] [, ...]] [, constraint multifieldindex [, ...]]) 其中，各类型type如下：<br>数据类型 type参数<br>整型 short<br>长整型 integer<br>单精度 float<br>双精度 double<br>字符串 text<br>日期 datetime<br>是/否 bit<br>货币 currency<br>系统自动编号 counter<br><br>五、 对列的操作：<br>1、 取得sql语句中的列数：<br>int superrecordset::getcolcount()<br>{<br>sword swcolcount;<br>if (m_hstmt == null)<br>return -1;<br>if (sql_success == ::sqlnumresultcols(m_hstmt,&swcolcount))<br>return swcolcount;<br>else<br>return -1;<br>}<br><br>七、数据的读取<br>1、列绑定：<br>cstring strsqlstring;<br>retcode returncode;<br>sqlhstmt hstmt;<br>if (sql_success != sqlallochandle(sql_handle_stmt,theapp.m_hdbc,&hstmt))<br>return;<br>ff_db_hhzhichu_set_fields dbdata;<br>sdword cb1;<br>sdword cb2;<br>sdword cb3;<br>sdword cb4;<br>sdword cb5;<br>sdword cb6;<br>sdword cb7;<br>sdword cb8;<br>sdword cb9;<br><br>// build the sql statement<br>strsqlstring.format(<br>"select "<br>"nid,"<br>"ariqi,"<br>"njine,"<br>"ashuoming,"<br>"alaiyuan,"<br>"acunzhe,"<br>"ayongtu,"<br>"axiaofei,"<br>"abeizhu"<br>" from hhzhichu "<br>" where nid=%u",<br>nid);<br><br>if (sql_success == (returncode = sqlexecdirect(hstmt,(uchar*)((lpctstr)strsqlstring),sql_nts)))<br>{<br>sqlbindcol(hstmt,1,sql_c_slong,&dbdata.m_nid,0,&cb1);<br>sqlbindcol(hstmt,2,sql_c_timestamp,&dbdata.m_ariqi,0,&cb2);<br>sqlbindcol(hstmt,3,sql_c_double,&dbdata.m_njine,0,&cb3);<br>sqlbindcol(hstmt,4,sql_c_char,dbdata.m_ashuoming,hhzhichu_ashuoming_size,&cb4);<br>sqlbindcol(hstmt,5,sql_c_char,dbdata.m_alaiyuan,hhzhichu_alaiyuan_size,&cb5);<br>sqlbindcol(hstmt,6,sql_c_char,dbdata.m_acunzhe,hhzhichu_acunzhe_size,&cb6);<br>sqlbindcol(hstmt,7,sql_c_char,dbdata.m_ayongtu,hhzhichu_ayongtu_size,&cb7);<br>sqlbindcol(hstmt,8,sql_c_char,dbdata.m_axiaofei,hhzhichu_axiaofei_size,&cb8);<br>sqlbindcol(hstmt,9,sql_c_char,dbdata.m_abeizhu,hhzhichu_abeizhu_size,&cb9);<br><br><br>// fetch and store...<br>if (sql_success == (returncode = sqlfetch(hstmt)))<br>{<br>m_record.m_nid = dbdata.m_nid;<br><br>m_record.m_ariqi.setdatetime(dbdata.m_ariqi.year,<br>dbdata.m_ariqi.month,<br>dbdata.m_ariqi.day,<br>dbdata.m_ariqi.hour,<br>dbdata.m_ariqi.minute,<br>dbdata.m_ariqi.second);<br><br>m_record.m_njine = dbdata.m_njine;<br>m_record.m_ashuoming = dbdata.m_ashuoming;<br>m_record.m_alaiyuan = dbdata.m_alaiyuan;<br>m_record.m_acunzhe = dbdata.m_acunzhe;<br>m_record.m_ayongtu = dbdata.m_ayongtu;<br>m_record.m_axiaofei = dbdata.m_axiaofei;<br>m_record.m_abeizhu = dbdata.m_abeizhu;<br><br>}<br>}<br>::sqlfreehandle(sql_handle_stmt,hstmt);<br><br>其中，如果cb1、cb2、cb3、cb4、cb5、cb6、cb7、cb8、cb9是接受返回的数据的大小的，如果他们的值等于sql_null_data，那么表示此记录的这个字段的值为空。<br><br>2、块绑定<br>cstuffbasicdataqry::cstuffbasicdataqry(codbcdatabase* pdb) : m_nrowsetsize(1000), m_pdatabase(pdb)<br>{<br>m_hstmt = sql_null_hstmt;<br>retcode returncode = sqlallochandle(sql_handle_stmt, m_pdatabase->gethdbc(), &m_hstmt);<br>if (returncode != sql_success)<br>trace("unable to allocate statement handle in cttttempset\n");<br>}<br><br>cstuffbasicdataqry::~cstuffbasicdataqry()<br>{<br>reset();<br>if (m_hstmt)<br>sqlfreehandle(sql_handle_stmt, m_hstmt);<br>}<br>void cstuffbasicdataqry::reset()<br>{<br>if (m_hstmt)<br>sqlfreehandle(sql_handle_stmt, m_hstmt);<br>for (int i = 0; i < m_adata.getsize(); i++)<br>delete m_adata.getat(i);<br>m_adata.removeall();<br>}<br>int cstuffbasicdataqry::load()<br>{<br>cstring strsqlstring;<br>//retcode returncode;<br>udword rowsfetched;<br>uword *prowstatus;<br>pff_db_stuffbasicdataqry_fields phostdata;<br><br>assert(m_nrowsetsize > 0);<br>prowstatus = new uword[m_nrowsetsize];<br>assert(prowstatus);<br>phostdata = new ff_db_stuffbasicdataqry_fields[m_nrowsetsize];<br>assert(phostdata);<br><br>sqlsetstmtoption(m_hstmt,sql_bind_type,sizeof(ff_db_stuffbasicdataqry_fields));<br>sqlsetstmtoption(m_hstmt,sql_concurrency,sql_concur_read_only);<br>sqlsetstmtoption(m_hstmt,sql_cursor_type,sql_cursor_keyset_driven);<br>sqlsetstmtoption(m_hstmt,sql_rowset_size,m_nrowsetsize);<br><br>strsqlstring.format(<br>"select * "<br>" from stuffbasicdata");<br><br>if (sql_success == sqlexecdirect(m_hstmt,(uchar*)((lpctstr)strsqlstring),sql_nts))<br>{<br>sqlbindcol(m_hstmt,1,sql_c_char,phostdata[0].m_astuffid,stuffbasicdataqry_astuffid_size,&phostdata[0].m_astuffidind);<br>sqlbindcol(m_hstmt,2,sql_c_char,phostdata[0].m_anamecn,stuffbasicdataqry_anamecn_size,&phostdata[0].m_anamecnind);<br>sqlbindcol(m_hstmt,3,sql_c_char,phostdata[0].m_anameen,stuffbasicdataqry_anameen_size,&phostdata[0].m_anameenind);<br>sqlbindcol(m_hstmt,4,sql_c_char,phostdata[0].m_aeducation,stuffbasicdataqry_aeducation_size,&phostdata[0].m_aeducationind);<br>sqlbindcol(m_hstmt,5,sql_c_char,phostdata[0].m_agender,stuffbasicdataqry_agender_size,&phostdata[0].m_agenderind);<br>sqlbindcol(m_hstmt,6,sql_c_timestamp,&phostdata[0].m_dworkdate,0,&phostdata[0].m_dworkdateind);<br>sqlbindcol(m_hstmt,7,sql_c_char,phostdata[0].m_adepartment,stuffbasicdataqry_adepartment_size,&phostdata[0].m_adepartmentind);<br>sqlbindcol(m_hstmt,8,sql_c_char,phostdata[0].m_abusiness,stuffbasicdataqry_abusiness_size,&phostdata[0].m_abusinessind);<br>sqlbindcol(m_hstmt,9,sql_c_char,phostdata[0].m_abusinesslevel,stuffbasicdataqry_abusinesslevel_size,&phostdata[0].m_abusinesslevelind);<br>sqlbindcol(m_hstmt,10,sql_c_char,phostdata[0].m_aworktype,stuffbasicdataqry_aworktype_size,&phostdata[0].m_aworktypeind);<br>sqlbindcol(m_hstmt,11,sql_c_timestamp,&phostdata[0].m_dleaveworkdate,0,&phostdata[0].m_dleaveworkdateind);<br>sqlbindcol(m_hstmt,12,sql_c_char,phostdata[0].m_aenagetype,stuffbasicdataqry_aenagetype_size,&phostdata[0].m_aenagetypeind);<br>sqlbindcol(m_hstmt,13,sql_c_timestamp,&phostdata[0].m_dcreatedocdate,0,&phostdata[0].m_dcreatedocdateind);<br><br>while (sql_success == sqlextendedfetch(m_hstmt,sql_fetch_next,1,&rowsfetched,prowstatus))<br>{<br>for (uint count = 0; count < rowsfetched; count++)<br>{<br>if (prowstatus[count] != sql_row_deleted && prowstatus[count] != sql_row_error )<br>{<br>pdb_stuffbasicdataqry_fields pdata = new db_stuffbasicdataqry_fields();<br>assert(pdata);<br><br>if (phostdata[count].m_astuffidind == sql_null_data)<br>pdata->m_astuffid = "";<br>else<br>pdata->m_astuffid = phostdata[count].m_astuffid;<br>if (phostdata[count].m_anamecnind == sql_null_data)<br>pdata->m_anamecn = "";<br>else<br>pdata->m_anamecn = phostdata[count].m_anamecn;<br>if (phostdata[count].m_anameenind == sql_null_data)<br>pdata->m_anameen = "";<br>else<br>pdata->m_anameen = phostdata[count].m_anameen;<br>if (phostdata[count].m_aeducationind == sql_null_data)<br>pdata->m_aeducation = "";<br>else<br>pdata->m_aeducation = phostdata[count].m_aeducation;<br>if (phostdata[count].m_agenderind == sql_null_data)<br>pdata->m_agender = "";<br>else<br>pdata->m_agender = phostdata[count].m_agender;<br>pdata->m_dworkdate.setdatetime(phostdata[count].m_dworkdate.year,<br>phostdata[count].m_dworkdate.month,<br>phostdata[count].m_dworkdate.day,<br>phostdata[count].m_dworkdate.hour,<br>phostdata[count].m_dworkdate.minute,<br>phostdata[count].m_dworkdate.second);<br>if (phostdata[count].m_adepartmentind == sql_null_data)<br>pdata->m_adepartment = "";<br>else<br>pdata->m_adepartment = phostdata[count].m_adepartment;<br>if (phostdata[count].m_abusinessind == sql_null_data)<br>pdata->m_abusiness = "";<br>else<br>pdata->m_abusiness = phostdata[count].m_abusiness;<br>if (phostdata[count].m_abusinesslevelind == sql_null_data)<br>pdata->m_abusinesslevel = "";<br>else<br>pdata->m_abusinesslevel = phostdata[count].m_abusinesslevel;<br>if (phostdata[count].m_aworktypeind == sql_null_data)<br>pdata->m_aworktype = "";<br>else<br>pdata->m_aworktype = phostdata[count].m_aworktype;<br>pdata->m_dleaveworkdate.setdatetime(phostdata[count].m_dleaveworkdate.year,<br>phostdata[count].m_dleaveworkdate.month,<br>phostdata[count].m_dleaveworkdate.day,<br>phostdata[count].m_dleaveworkdate.hour,<br>phostdata[count].m_dleaveworkdate.minute,<br>phostdata[count].m_dleaveworkdate.second);<br>if (phostdata[count].m_aenagetypeind == sql_null_data)<br>pdata->m_aenagetype = "";<br>else<br>pdata->m_aenagetype = phostdata[count].m_aenagetype;<br>pdata->m_dcreatedocdate.setdatetime(phostdata[count].m_dcreatedocdate.year,<br>phostdata[count].m_dcreatedocdate.month,<br>phostdata[count].m_dcreatedocdate.day,<br>phostdata[count].m_dcreatedocdate.hour,<br>phostdata[count].m_dcreatedocdate.minute,<br>phostdata[count].m_dcreatedocdate.second);<br><br>m_adata.add(pdata);<br>}<br>}<br>if (rowsfetched < (uint)m_nrowsetsize)<br>break;<br>}<br>}<br>delete [] prowstatus;<br>delete [] phostdata;<br>return m_adata.getsize();<br>}<br><br>八、写数据库<br>1、普通方法：<br>cstring strsql="insert into table (file1,file2,file3) values (value1,value2,value3)"<br><br>long executesql(sqlhdbc hdbc,cstring strsql)<br>{<br>sqlreturn returncode;<br>sqlhstmt m_hstmt;<br>bool breturn = false;<br>long nrowcount = 0;<br>if (sql_success == (returncode = ::sqlallochandle(sql_handle_stmt,hdbc,&m_hstmt)))<br>{<br>if (sql_success == (returncode = ::sqlexecdirect(m_hstmt, (uchar*)((lpctstr)strsql),sql_nts)))<br>{<br>breturn = true;<br>::sqlrowcount(m_hstmt,&nrowcount);<br>}<br>}<br>returncode = ::sqlfreehandle(sql_handle_stmt,m_hstmt);<br><br>// if (!breturn) nrowcount = 0;<br>return nrowcount;<br>}<br>注意，要把字段赋为空，字符串、日期应是null，可以用下面的函数修改：<br>cstring verifysqlstr(cstring strsql)<br>{<br>int nlength = strsql.getlength();<br>int n1 = 0;//check '';<br>int n2 = 0;<br>int m1 = 0;//check ##;<br>int m2 = 0;<br>for (int i = 0; i< nlength;i++)<br>{<br>if (strsql[i] == 39)<br>{<br>n2 = i;<br>if (n2-n1 == 1)<br>{<br>strsql.delete(n1,2);<br>strsql.insert(n1,"null");<br>nlength +=2;<br>n1 = n2;<br>}<br>else<br>{<br>n1 = n2;<br>}<br>}<br>if (strsql[i] == '#')<br>{<br>m2 = i;<br>if (m2-m1 == 1)<br>{<br>strsql.delete(m1,2);<br>strsql.insert(m1,"null");<br>nlength +=2;<br>m1 = m2;<br>}<br>else<br>{<br>m1 = m2;<br>}<br>}<br>}<br>return strsql;<br>}<br><br>2、参数绑定：<br>bool ccddataset::insert(pdb_cddata_set_fields pdata, bool bfirsttime /* true */)<br>{<br>retcode returncode;<br>cstring strsqlstring;<br>static ff_db_cddata_set_fields hostdata;<br><br><br>// prepare the statement and bind the columns once<br>if (bfirsttime)<br>{<br>memset(&hostdata,0,sizeof(hostdata));<br>sqlfreestmt(m_hstmt, sql_close); // close the cursor if any<br>sqlfreestmt(m_hstmt, sql_reset_params); // reset the statement handle<br>strsqlstring.format("insert into cddata ("<br>"nguangpan,"<br>"nwenjian,"<br>"nclass,"<br>"awenjian,"<br>"nshangji,"<br>"nshuxing,"<br>"abeizhu )"<br>"values ("<br>"?," // nguangpan<br>"?," // nwenjian<br>"?," // nclass<br>"?," // awenjian<br>"?," // nshangji<br>"?," // nshuxing<br>"? )" // abeizhu<br>); // end format<br><br>returncode = sqlprepare(m_hstmt, (uchar*)((lpctstr)strsqlstring),sql_nts);<br>if (returncode != sql_success)<br>{<br>return false;<br>}<br><br>sqlbindparameter(m_hstmt,1, sql_param_input, sql_c_slong, sql_integer, 0,<br>0,&hostdata.m_nguangpan,0,&hostdata.m_nguangpanind );<br>sqlbindparameter(m_hstmt, 2,sql_param_input,sql_c_slong,sql_integer, 0,<br>0,&hostdata.m_nwenjian,0, &hostdata.m_nwenjianind );<br>sqlbindparameter(m_hstmt,3,sql_param_input, sql_c_slong,sql_integer, 0,<br>0,&hostdata.m_nclass,0,&hostdata.m_nclassind );<br>sqlbindparameter(m_hstmt,4,sql_param_input,sql_c_char,sql_varchar,<br>cddata_awenjian_size,0,hostdata.m_awenjian,0,&hostdata.m_awenjianind );<br>sqlbindparameter(m_hstmt,5,sql_param_input,sql_c_slong,sql_integer,0,<br>0,&hostdata.m_nshangji, 0, &hostdata.m_nshangjiind );<br>sqlbindparameter(m_hstmt,6,sql_param_input,sql_c_slong,sql_integer, 0,<br>0, &hostdata.m_nshuxing, 0,&hostdata.m_nshuxingind );<br>sqlbindparameter(m_hstmt, 7,sql_param_input,sql_c_char,sql_varchar,<br>cddata_abeizhu_size,0, hostdata.m_abeizhu, 0,&hostdata.m_abeizhuind );<br><br>}<br><br>// move the data to host structure and execute the statement<br>hostdata.m_nguangpan = pdata->m_nguangpan;<br>hostdata.m_nwenjian = pdata->m_nwenjian;<br>hostdata.m_nclass = pdata->m_nclass;<br>hostdata.m_awenjianind = sql_nts;<br>memcpy(hostdata.m_awenjian, pdata->m_awenjian, cddata_awenjian_size);<br>hostdata.m_nshangji = pdata->m_nshangji;<br>hostdata.m_nshuxing = pdata->m_nshuxing;<br>hostdata.m_abeizhuind = sql_nts;<br>memcpy(hostdata.m_abeizhu, pdata->m_abeizhu, cddata_abeizhu_size);<br><br>returncode = sqlexecute(m_hstmt);<br>if (returncode != sql_success)<br>{<br>return false;<br>}<br><br>return true;<br><br>}<br><br><br>九、其他操作：<br><br>1、检测sql错误：<br>void displayerror(sqlreturn nresult, sword fhandletype, sqlhandle handle)<br>{<br>uchar szerrstate[sql_sqlstate_size+1]; // sql error state string<br>uchar szerrtext[sql_max_message_length+1]; // sql error text string<br>char szbuffer[1000];<br>char szdispbuffer[1000]; // display buffer<br>// formatted error text buffer<br>sword werrmsglen; // error message length<br>long dwerrcode; // native error code<br>int isize; // display error text size<br>sqlreturn nerrresult; // return code from sqlgetdiagrec<br>sword smsgnum = 1;<br>sword ffirstrun = true;<br><br>szbuffer[0] = '\0';<br><br>do<br>{<br>// continue to bring messageboxes till all errors are displayed.<br>// more than one message box may be reqd. as err text has fixed<br>// string size.<br><br>// initialize display buffer with the string in error text buffer<br>strcpy(szdispbuffer, szbuffer);<br><br>// call sqlgetdiagrec function with proper odbc handles, repeatedly until<br>// function returns sql_no_data. concatenate all error strings<br>// in the display buffer and display all results.<br>while ((nerrresult = sqlgetdiagrec(fhandletype, handle, smsgnum++,<br>szerrstate, &dwerrcode, szerrtext,<br>sql_max_message_length-1, &werrmsglen))<br>!= sql_no_data) {<br><br><br>if(nerrresult == sql_error ¦¦ nerrresult == sql_invalid_handle)<br>break;<br><br>wsprintf(szbuffer, sqlerr_format, (lpstr)szerrstate, dwerrcode, (lpstr)szerrtext);<br>isize = strlen(szdispbuffer);<br>if (isize && (isize+strlen(szbuffer)+1) >= 1000)<br>break;<br>if (isize)<br>strcat(szdispbuffer, "\n");<br>strcat(szdispbuffer, szbuffer);<br>}<br><br>// display proper error or warning message with proper title<br><br>if (nresult == sql_success_with_info)<br>messagebox(null, szdispbuffer, (ffirstrun? sqlwrnmsgtitle : sqlwrncntdtitle),<br>mb_ok ¦ mb_iconinformation);<br>else<br>messagebox(null, szdispbuffer, (ffirstrun? sqlerrmsgtitle : sqlerrcntdtitle),<br>mb_ok ¦ mb_iconexclamation);<br><br>if (ffirstrun)<br>ffirstrun = false;<br>}<br>while (!(nerrresult == sql_no_data ¦¦ nerrresult == sql_error ¦¦ nerrresult == sql_invalid_handle));<br>}<br>分配和释放语句<br><br>任何与处理和传递sql语句相关的sql函数都要求一个有效的语句句柄作为<br>参数。语句句柄很象环境或连接句柄，区别之处在于它引用sql语句或者其它<br>返回结果的odbc函数。一个连接句柄可以与几个语句句柄相关连，但每一个<br>语句句柄只能与一个连接句柄相关连。应用系统要想分配语句句柄，只需调用<br>下面描述的sqlallocstmt即可。 <br><br>sqlallocstmt为语句句柄分配内存存储区，并将此句柄与连接句柄指定的<br>连接联系在一起。应用系统必须先用sqlallocstmt为sql语句分配内存，然后<br>才能提供引用某一特殊语句句柄的sql语句。<br><br>sqlallocstmt的语法如下：<br>retcode sqlallocstmt（hdbc，phstmt）<br>sqlallocstmt的返回码为：<br>sql-success<br>sql-success-with-info<br>sql-invalid-handle<br>sql-error <br><br><br>sqlfreestmt<br><br>sqlfreestmt完成以下动作：<br>.停止任何与指定语句句柄相关的、当前正在处理的sql语句；<br>关闭任何与指定语句句柄相关的打开光标；<br>舍弃所有未完成的结果。<br>有选择的释放与指定语句句柄相关的所有资源；<br><br>sqlfreestmt的语法为：<br>retcode sqlfreestmt（hstmt,foption) <br>sqlfreestmt的返回码是：<br>sql-success<br>sql-success-with-info<br>sql-invalid-handle<br>sql-error <br><br>最后 <br><br>在我们的开发系统appbuilder中你可以不必对上面的复杂的过程进行完整的了解，你也不必书写任何的调用代码，我们将这一切都自动为你产生，同时还和开发最终程序的界面融合在一起，一切都非常简单。为你的开发自动编写大量的代码，如果你需要看看，请到:www.ucancode.com中下在一个免费的版本。 <br><br><br>
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