ST_MLineFromWKB function
The ST_MLineFromWKB function takes a well-known binary representation of a multilinestring and, optionally, a spatial reference system identifier as input parameters and returns the corresponding multilinestring.
If the given well-known binary representation is null, then null is returned.
The recommended function for achieving the same result is the ST_MultiLineString function. It is recommended because of its flexibility: ST_MultiLineString takes additional forms of input as well as the well-known binary representation.
Syntax
Parameters
- wkb
- A value of type BLOB(2G) that contains the well-known binary representation of the resulting multilinestring.
- srs_id
- A value of type INTEGER that identifies the spatial reference
system for the resulting multilinestring.
If the srs_id parameter is omitted, the spatial reference system with the numeric identifier 0 (zero) is used.
If the specified srs_id does not identify a spatial reference system listed in the catalog view DB2GSE.ST_SPATIAL_REFERENCE_SYSTEMS, then an exception condition is raised (SQLSTATE 38SU1).
Return type
db2gse.ST_MultiLineString
Example
In the following example, the lines of results have been reformatted for readability. The spacing in your results will vary according to your online display.
- Line 1: (61, 2) (64, 3) (65, 6)
- Line 2: (58, 4) (59, 5) (61, 8)
- Line 3: (69, 3) (67, 4) (66, 7) (68, 9)
SET CURRENT FUNCTION PATH = CURRENT FUNCTION PATH, db2gse
CREATE TABLE sample_mlines (id INTEGER, geometry ST_MultiLineString,
wkb BLOB(32K))
INSERT INTO sample_mlines
VALUES (10, ST_MultiLineString ('multilinestring
( (61 2, 64 3, 65 6),
(58 4, 59 5, 61 8),
(69 3, 67 4, 66 7, 68 9) )', 1) )
UPDATE sample_mlines AS temporary_correlated
SET wkb = ST_AsBinary( geometry )
WHERE id = temporary_correlated.id
SELECT id, CAST( ST_AsText( ST_MLineFromWKB (wkb) )
AS VARCHAR(280) ) MULTI_LINE_STRING
FROM sample_mlines
WHERE id = 10
ID MULTI_LINE_STRING
---------- --------------------------------------------------------------------
10 MULTILINESTRING (( 61.00000000 2.00000000, 64.00000000 3.00000000,
65.00000000 6.00000000),
( 58.00000000 4.00000000, 59.00000000 5.00000000,
61.00000000 8.0000000),
( 69.00000000 3.00000000, 67.00000000 4.00000000,
66.00000000 7.00000000, 68.00000000 9.00000000 ))