笔记：一些access操作，基于DAO

鉴于csdn博客更新之于本人来讲是一个失败，导致本博文排版一片混乱。现将其转到http://www.cnblogs.com/tigeryth/archive/2011/07/11/2102863.html

1. 获得所有的数据表的名称，并基于表名来进一步操作。

if(!db.IsOpen())db.Open(_T("hydata"));CDaoTableDefInfo tablename;CString name;short ncount = db.GetTableDefCount();for (short i = 0; i < ncount; i++){db.GetTableDefInfo(i,tablename,AFX_DAO_PRIMARY_INFO);if (tablename.m_strName.Left(2) == _T("00")){m_strCodeArray_SZ.Add(tablename.m_strName);} else if(tablename.m_strName.Left(1) == _T("6"))m_strCodeArray_SH.Add(tablename.m_strName);} 

2. 为数据表增加某些字段（field）。

CDaoTableDef tabledef(&db); // CDaoTableDef 和 CDaoFieldInfo成对出现CDaoFieldInfo fieldinfo;fieldinfo.m_strName = _T("increase");fieldinfo.m_nType = dbLong;fieldinfo.m_lSize = dbLong;fieldinfo.m_lAttributes = dbUpdatableField;fieldinfo.m_bAllowZeroLength = FALSE;fieldinfo.m_bRequired = FALSE;fieldinfo.m_nOrdinalPosition = 23; // 添加的新field在第23列tabledef.Open(_T("000016"));tabledef.CreateField(fieldinfo);//另外一种方式增加新field: 利用现有的fieldCDaoFieldInfo info;tabledef.GetFieldInfo(15,info,AFX_DAO_SECONDARY_INFO);info.m_nOrdinalPosition = 24;info.m_strName = _T("increase2");tabledef.CreateField(info); 

3. 判断某字段的一些记录是否为空，是则补充数据。

CDaoRecordset ret(&db);CString sql = _T("SELECT * FROM 000016");ret.Open(dbOpenDynaset,sql,0);COleVariant varMa,var;ret.MoveLast();ret.GetFieldValue(17,varMa);while (varMa.vt == VT_NULL){long tt = 2;var = COleVariant(tt,VT_I4);ret.Edit();ret.SetFieldValue(17,var);ret.Update();ret.MovePrev();ret.GetFieldValue(17,varMa);} 

4. 创建具有同样表结构的新表

db.Execute(_T("SELECT * INTO 新表 FROM 旧表 WHERE 1=2")); 

5. 修改表名

CDaoTableDef def(&db);CDaoTableDefInfo definfo;short ncount = db.GetTableDefCount();for (short i = 0; i < ncount; i++){db.GetTableDefInfo(i,definfo,AFX_DAO_PRIMARY_INFO);if (definfo.m_strName.Left(1) == _T("0")){CString strname;strname.Format(_T("sz%s"),definfo.m_strName);def.Open(definfo.m_strName);def.SetName(strname);def.Close();} else if (definfo.m_strName.Left(1) == _T("6")){CString strname;strname.Format(_T("sh%s"),definfo.m_strName);def.Open(definfo.m_strName);def.SetName(strname);def.Close();}} 

6. 判断表是否存在。否，则创建之

CDaoTableDef   td(   &db   ); try {     td.Open(   "login1 "   ); } catch(   CDaoException*   e   ) {     //如果不存在该表 ,下面是创建表的代码段    e-> Delete(   ); } td.Close(   ); 

7. ...待更新。