insvalexample.htm

来自「The goal of this library is to make ODBC」· HTM 代码 · 共 26 行

<pre><code><span class="codeComment">// Enforce business rule for inserted rows</span>

class Example
{
  public:					<span class="codeComment">// tablename.columnname:</span>
	int exampleInt;	    			<span class="codeComment">// DB_EXAMPLE.INT_VALUE</span>
	string exampleStr;			<span class="codeComment">// DB_EXAMPLE.STRING_VALUE</span>
	double exampleDouble;			<span class="codeComment">// DB_EXAMPLE.DOUBLE_VALUE</span>
	long exampleLong;			<span class="codeComment">// DB_EXAMPLE.EXAMPLE_LONG</span>
	TIMESTAMP_STRUCT exampleDate;		<span class="codeComment">// DB_EXAMPLE.EXAMPLE_DATE</span>
};

<span class="codeComment">// specialization of DefaultInsValidate for Example
// can have any number of InsValidate functions for a single data class just as with
// ParamObj's ... below is general business rule constraint we wish to enforce for all Examples</span>
template&lt;&gt; class dtl::DefaultInsValidate&lt;Example&gt; {
public: 
bool operator()(Example &amp;rowbuf)
{
	<span class="codeComment">// data is valid if rowbuf.exampleStr is nonempty and rowbuf.exampleDouble is 
	// between 0 and 100 (like a percentage)</span>
	return (rowbuf.exampleStr.length() &gt; 0 &amp;&amp; rowbuf.exampleDouble &gt;= 0.0 &amp;&amp;
		rowbuf.exampleLong &lt;= 100.0);
}
};
</code></pre>