在这里插入代码片```sql
SELECT ST_AsText(ST_Centroid(ST_GeomFromText('GEOMETRYCOLLECTION(LINESTRING(105.400538 26.965642, 105.376419 26.938482, 105.350328 26.911685, 105.329089 26.879879, 105.313625 26.84789, 105.301742 26.813179, 105.292141 26.775107, 105.285816 26.733533, 105.285408 26.690106, 105.294777 26.643773, 105.31476 26.599119, 105.343749 26.554512, 105.378797 26.510962, 105.406857 26.476005, 105.425623 26.445117, 105.436415 26.418288, 105.44132 26.39957, 105.443848 26.3814, 105.445808 26.366106, 105.447354 26.352505, 105.448556 26.339266, 105.448934 26.326249, 105.448698 26.312655, 105.443828 26.293889, 105.436926 26.270218, 105.430748 26.246634, 105.42704 26.226611, 105.424913 26.206425, 105.424631 26.185484, 105.428987 26.16029, 105.436236 26.137537, 105.441157 26.11861, 105.441794 26.105338, 105.44037 26.09359, 105.433558 26.079511, 105.421328 26.063383, 105.413106 26.055413), POLYGON((106.708375 26.839121, 106.683267 26.810694, 106.661883 26.780294, 106.646901 26.740893, 106.638973 26.687263, 106.635943 26.625593, 106.635916 26.561664, 106.641727 26.503779, 106.65188 26.4642, 106.664116 26.438558, 106.686874 26.417503, 106.739428 26.403494, 106.801648 26.410653, 106.864537 26.4289, 106.923511 26.461191, 106.976723 26.505678, 107.026214 26.56542, 107.068035 26.633192, 107.100928 26.69656, 107.123849 26.751382, 107.13434 26.79801, 107.134828 26.835701, 107.124045 26.869121, 107.102829 26.897353, 107.071789 26.918661, 107.031575 26.93271, 106.986814 26.939985, 106.949099 26.946479, 106.708375 26.839121)), POLYGON((105.930234 26.761077, 105.734432 26.453281, 106.019679 26.357196, 106.250558 26.639687, 105.930234 26.761077)))')));

结果为：