How to set a point as default value for a geography column?

Question

I have this SQL command that creates a table with a GEOGRAPHY -type column for spatial data that is meant to store a latitude/longitude pair (a point). How can I set a default value for that column? For example, a point at (0,0)?

CREATE TABLE [dbo].[StationLocations] (
    [Id] [int] NOT NULL,
    [StationId] [int] NOT NULL,
    [Position] [Geography],
CONSTRAINT [PKStationLocations] PRIMARY KEY CLUSTERED ([Id]))

Answer 1

try this:

CREATE TABLE #TEMP(ID INT,COL1 GEOGRAPHY DEFAULT(CONVERT(GEOGRAPHY,'POINT (0 0)')))
INSERT INTO #TEMP (ID) VALUES(1)
SELECT * FROM #TEMP
ID  COL1
1   0xE6100000010C00000000000000000000000000000000

SELECT ID,CONVERT(VARCHAR,COL1) AS DEF_VALUE FROM #TEMP
ID  DEF_VALUE
1   POINT (0 0)

In your case

CREATE TABLE [dbo].[StationLocations] (
    [Id] [int] NOT NULL,
    [StationId] [int] NOT NULL,
    [Position] [Geography] DEFAULT(CONVERT(GEOGRAPHY,'POINT (0 0)')),
CONSTRAINT [PKStationLocations] PRIMARY KEY CLUSTERED ([Id]))

Answer 2

Not sure if this is the best method but, using this answer as a reference, you could define it like this :

ALTER TABLE dbo.StationLocations
ADD CONSTRAINT DF_StationLocations_Position
DEFAULT geography::STPointFromText('POINT (0 0)', 4326) FOR Position
;

Answer 3

I don't think you can do it directly. You could use an insert trigger in a roundabout way, but it's not a completely satisfactory solution.