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<p class="MsoNormal">So, when you get into implementation of an RFC you notice things. One thing that has come up is ambiguity around the way native SQL is specified. In older versions of MapServer you’d set FILTER with a string value and the underlying driver
would interpret that as SQL. Easy enough at first glance. RFC 91 aims to enable translation from MapServer expression syntax to native SQL plus handling FILTER merging with query operations. That’s where the ambiguity sets in – it’s not clear how you define
native SQL, even the codebase handled it differently. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">That ticket aims talks about ways to resolve this ambiguity and you can see the full discussion here: <a href="https://github.com/mapserver/mapserver/issues/5001">https://github.com/mapserver/mapserver/issues/5001</a>. Ultimately we arrived
at a point where we needed to bring the discussion back to the list. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Here’s a summary of potential options:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Do nothing, live with the ambiguity and resulting code complexity.<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Adopt the current OGR method of prefixing the FILTER string with “WHERE “.<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Adopt a new delimiter (e.g. <>) to explicitly define native SQL.<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">4.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Remove the ability to set native SQL altogether – FILTERs would use MapServer expression syntax only and we rely on translations.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Option 4 sounds drastic but probably gets us the most streamlined code to maintain – merging is much more straight forward. The native SQL in FILTER functionality was added long ago before more complex DATA handling was implemented. It’s
easy to argue that since all of the drivers that support some sort of SQL do so in the DATA definition that there’s no need for native SQL FILTERs at all.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Why now? We’ll we only want to break things at major releases so…<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Steve<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span style="font-size:8.0pt;text-transform:uppercase;letter-spacing:.2pt">StEVE LIME
<span style="color:#990033">| </span></span></b><span style="font-size:8.0pt;text-transform:uppercase;letter-spacing:1.0pt">DATA & Applications MANAGER</span><span style="font-size:8.0pt;font-family:"Arial","sans-serif";text-transform:uppercase;letter-spacing:1.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.0pt;text-transform:uppercase;letter-spacing:1.0pt">MN.IT Services
<span style="color:#990033">@ </span>MnDNR</span><span style="font-size:7.0pt;font-family:"Corbel","sans-serif""><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-top:1.0pt;line-height:110%"><span style="font-size:7.0pt;line-height:110%">651-259-5473 (w)
<b>|</b> 651-297-4946 (f) <b>|</b> </span><a href="mailto:Your.name@state.mn.us"><span style="font-size:7.0pt;line-height:110%">steve.lime@state.mn.us</span></a><span style="font-size:7.5pt;line-height:110%;font-family:"Corbel","sans-serif";color:#5C83B4;text-transform:uppercase;letter-spacing:1.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal"><a href="http://www.mn.gov/oet"><i><span style="font-size:8.0pt;font-family:"Corbel","sans-serif";color:#5C83B4;letter-spacing:1.0pt;text-decoration:none"><img border="0" width="117" height="42" id="Picture_x0020_5" src="cid:image001.jpg@01CFD7D1.EA74E5E0"></span></i></a><i><span style="font-size:8.0pt;font-family:"Corbel","sans-serif";color:#5C83B4;letter-spacing:1.0pt"><o:p></o:p></span></i></p>
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<p class="MsoNormal"><span style="font-size:8.0pt">Information Technology for Minnesota Government
</span><span style="font-size:7.0pt"> <b>|</b> </span><span style="font-size:8.0pt;letter-spacing:1.0pt"> </span><a href="http://www.mn.gov/oet"><span style="font-size:8.0pt">mn.gov/oet</span></a><span style="font-size:8.0pt;color:#5C83B4;letter-spacing:1.0pt"><o:p></o:p></span></p>
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