ST_LINEFROMTEXT

Description

Converts a WKT (Well Known Text) string into an in-memory representation of a Line

Alias

• ST_LINESTRINGFROMTEXT

Syntax

ST_LINEFROMTEXT( <wkt>)

Parameters

Parameters	Description
<wkt>	A WKT string conforming to the LINESTRING type, formatted as:
"LINESTRING (x1 y1, x2 y2)"
Where (x1 y1), (x2 y2) are the vertex coordinates of the line segment. Coordinate values are numeric (integers or decimals).

Return value

Returns a geometric object of type Line, which is stored in memory in Doris's internal spatial data format. It can be directly passed as a parameter to other spatial functions (such as ST_LENGTH, ST_INTERSECTS, etc.) for calculations.

• Returns NULL if the input WKT string is invalid (e.g., fewer than 2 vertices, syntax errors, non-numeric coordinates, etc.).
• Returns NULL if is NULL or an empty string.

Example

Normal LINE type

mysql> SELECT ST_AsText(ST_LineFromText("LINESTRING (1 1, 2 2)"));
+-----------------------------------------------------+
| ST_AsText(ST_LineFromText("LINESTRING (1 1, 2 2)")) |
+-----------------------------------------------------+
| LINESTRING (1 1, 2 2)                               |
+-----------------------------------------------------+

Invalid WKT (insufficient vertices)

mysql> SELECT ST_LineFromText("LINESTRING (1 1)");
+-------------------------------------+
| ST_LineFromText("LINESTRING (1 1)") |
+-------------------------------------+
| NULL                                |
+-------------------------------------+

Invalid WKT (syntax error)

mysql> SELECT ST_LineFromText("LINESTRING (1 1, 2 2");
+-----------------------------------------+
| ST_LineFromText("LINESTRING (1 1, 2 2") |
+-----------------------------------------+
| NULL                                    |
+-----------------------------------------+

LineString with multiple vertices

mysql> SELECT ST_AsText(ST_LineFromText('LINESTRING (1 1, 2 2)'));
+-----------------------------------------------------+
| ST_AsText(ST_LineFromText('LINESTRING (1 1, 2 2)')) |
+-----------------------------------------------------+
| LINESTRING (1 1, 2 2)                               |
+-----------------------------------------------------+

Input NULL

mysql> SELECT ST_LineFromText(NULL);
+-----------------------+
| ST_LineFromText(NULL) |
+-----------------------+
| NULL                  |
+-----------------------+