QGIS/resources/function_help/json/line_merge

{
  "name": "line_merge",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Returns a LineString or MultiLineString geometry, where any connected LineStrings from the input geometry have been merged into a single linestring. This function will return NULL if passed a geometry which is not a LineString/MultiLineString.",
  "arguments": [{
    "arg": "geometry",
    "description": "a LineString/MultiLineString geometry"
  }],
  "examples": [{
    "expression": "geom_to_wkt(line_merge(geom_from_wkt('MULTILINESTRING((0 0, 1 1),(1 1, 2 2))')))",
    "returns": "'LineString(0 0,1 1,2 2)'"
  }, {
    "expression": "geom_to_wkt(line_merge(geom_from_wkt('MULTILINESTRING((0 0, 1 1),(11 1, 21 2))')))",
    "returns": "'MultiLineString((0 0, 1 1),(11 1, 21 2)'"
  }],
  "tags": ["passed", "single", "return", "input", "linestrings", "merged", "connected", "linestring", "multilinestring"]
}