More information. This shows up in my server error_log when I try to change the sorting of a property listing page:
WordPress database error You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'UNDEFINED
LIMIT 0, 10' at line 5 for query
SELECT p.ID , (SELECT pm.meta_value FROM wp_postmeta AS pm WHERE pm.post_id = p.ID AND pm.meta_key = 'area' LIMIT 1 ) as meta_value
FROM wp_posts AS p
WHERE p.ID IN ( 2009,4297,4478,4476,4697,4716,4872,5027,5028,5030,5050,5051,5054,5056,5059,5061,5074,5085,5088,5090,5092,5094,5096,5086,5122,5224,5338,5382,5457,5446,5488,5588,5234,5599,5601,5602,5656,5448,5659,5735,1347,1394,1418,1429,1435,1446,1458,1457,1460,1462,1464,1466,1468,1470,1477,1479,1494,1506,1547,1550,1589,1612,1603,1672,1673,1698,1724,1741,1752,1763,1806,1816,1818,1844,1862,1870,1876,1878,1888,1899,1919,1957,1966,1998,2023,2056,2071,2073,2075,2077,2079,2081,2083,2086,2088,2090,2092,2094,2204,2117,2219,2261,2267,2271,2284,2285,2308,2318,2330,2399,2342,2467,2503,2544,2556,2607,2648,2663,2715,2757,2759,2768,2794,2799,2800,2843,2853,2932,2957,3005,3010,2995,3011,3016,3051,3110,3117,3145,3147,3150,3156,3161,3164,3167,3174,3195,3215,3242,3313,3329,3359,3365,3392,3469,3483,3540,3547,3555,3556,3569,3658,3672,3753,3755,3760,3773,3814,3831,3834,3884,3932,3938,3973,3976,3978,3980,4023,4025,4035,4058,4093,4109,4144,4158,4195,4205,4239,4267,4269,4270,4287,4301,4313,4315,4385,4405,4413,4415,4451,4454,4456,4460,4462,4466,4468,4474,4480,4482,4484,4486,4488,4516,4517,4464,4520,4565,4632,4634,4679,4702,4703,4713,4720,4867,4929,4932,5034,5047,5062,5082,5207,5227,5228,5230,5231,5232,5380,5450,5451,5454)
AND p.post_status = 'publish'
ORDER BY meta_value UNDEFINED
LIMIT 0, 10;
made by do_action('wp_ajax_wpp_property_overview_pagination'), call_user_func_array, WPP_Core->ajax_property_overview, WPP_Core::shortcode_property_overview, WPP_F::get_properties
