subject_22502.htm

一些关于vc的问答

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序号：22502 发表者：jxhebin 发表日期：2002-11-26 14:56:19
<br>主题：vc++中用ADO创建数据库时，如何使得字段能为sql保留字段，以及如何使字段允许空字符串
<br>内容：在vc++中用ADO创建数据库时，当字段为sql保留字时，就产生错误。后来使用ADOX能<BR>解决这个问题，但是却不知道ADOX中如何设置字段属性，包括字段允许空字符串，以及字段缺省值的设置等等。请高手帮忙给出建议<BR>
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<font color=red>答案被接受</font><br>回复者：lasery 回复日期：2002-11-26 15:49:01
<br>内容：m_Col.CreateInstance(__uuidof(Column));&nbsp;&nbsp;&nbsp;&nbsp;<BR>m_Index.CreateInstance(__uuidof(Index));<BR>m_Table = m_Catalog-&gt;GetTables()-&gt;GetItem(_variant_t(myTableName));<BR>m_Col-&gt;Name =&nbsp;&nbsp;myFieldName;<BR>m_Col-&gt;ParentCatalog = m_Catalog; <BR>if( FieldType == TYPE_AutoIncrement)<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; m_Col-&gt;Type = adInteger;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Col-&gt;Properties-&gt;Item[_T("AutoIncrement")]-&gt;Value = true;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Table-&gt;Columns-&gt;Append(static_cast&lt;IUnknown *&gt;(m_Col), adInteger,0);<BR>}<BR>if (FieldType == adInteger)<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Col-&gt;Type = adInteger;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Col-&gt;Properties-&gt;Item[_T("Nullable")]-&gt;Value = true;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Table-&gt;Columns-&gt;Append(static_cast&lt;IUnknown *&gt;(m_Col), adInteger,0);<BR>}<BR>if (FieldType == adLongVarWChar)<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Col-&gt;Type = adLongVarWChar;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Col-&gt;Properties-&gt;Item[_T("Nullable")]-&gt;Value = true;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Col-&gt;Properties-&gt;Item[_T("Jet OLEDB:Allow Zero Length")]-&gt;Value = true;<BR>&nbsp;&nbsp;&nbsp;&nbsp;m_Table-&gt;Columns-&gt;Append(static_cast&lt;IUnknown *&gt;(m_Col), adLongVarWChar,0);<BR>}&nbsp;&nbsp;&nbsp;&nbsp;
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回复者：jxhebin 回复日期：2002-11-26 15:52:28
<br>内容：谢谢lasery
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