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<H2>4.6. Range Searching</H2>
<P>Range searching allows qualification of search returns with a field that must be within a certain numeric or alphanumeric range. To use it, set the <TT>mv_range_look</TT> variable to the products database field, or a column/field number for another file. Then, set the corresponding <TT>mv_range_min</TT> and <TT>mv_range_max</TT> variables with a selectable field.</P>
<PRE>
<INPUT TYPE="hidden" NAME="mv_range_look" VALUE="price">
Search on Price
Min <SELECT NAME="mv_range_min">
<OPTION value=0 SELECTED> Free
<OPTION value=1000000> $1,000,000
<OPTION value=10000000> $10,000,000
<OPTION value=20000000> $20,000,000
<OPTION value=40000000> $40,000,000
</SELECT><BR>
Max <SELECT NAME="mv_range_max">
<OPTION value=0 SELECTED> no object
<OPTION value=1000000> $1,000,000
<OPTION value=10000000> $10,000,000
<OPTION value=20000000> $20,000,000
<OPTION value=40000000> $40,000,000
</SELECT>
</PRE>
<P>The value of 0 for <TT>mv_range_max</TT> is equivalent to infinity if doing a numeric search. This makes it impossible to search for a ceiling of 0 with a negative <TT>mv_range_min</TT>.</P>
<P>The fields are stackable, so more than one range to check can be set. The order is significant, in the sense that the array of field names and minimum/maximum values must be kept in order to achieve correspondence.</P>
<P>The optional <TT>mv_range_alpha</TT> specification allows alphanumeric range matching for the corresponding field. If it is set, and the fields are stacked, they must all be set. The <TT>mv_case</TT> field does apply if it is set. Otherwise, the comparison is without regard to case.</P>
<P>If ONLY a range search is required, all lines with <TT>mv_return_all</TT>=yes must be selected in order to make the search operate. Range-only searches will be quite slow for large databases since every line must be scanned. It should be quite usable for catalogs of less than 10,000 items in size on a fast machine. Using it in combination with another search technique (in the same query) will yield faster search returns.</P>
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