martin/tests/fixtures/functions/function_zxy_query_test.sql
Yuri Astrakhan 2ee517d135
Support z,x,y and record-returning funcs, table rework (#380)
Can now handle several additional Postgres functions to get a tile, plus
tons of small fixes

### Multiple result variants
* `getmvt(z,x,y) -> [bytea,md5]`  (single row with two columns)
* `getmvt(z,x,y) -> [bytea]` (single row with a single column)
* `getmvt(z,x,y) -> bytea` (value)

### Multiple input parameter variants
* `getmvt(z, x, y)` or `getmvt(zoom, x, y)` (all 3 vars must be
integers)
* `getmvt(z, x, y, url_query)`, where instead of `url_query` it could be
any other name, but must be of type JSON

### Breaking
* srid is now the same type as PG -- `i32`
* renamed config vals `table_sources` and `function_sources` into
`tables` and `functions`

### Features and fixes
* if postgis is v3.1+, uses margin parameter to extend the search box by
the size of the buffer. I think we should make 3.1 minimal required.
* fixes feature ID issue from #466
* fixes mixed case names for schemas, tables and columns, functions and
parameter names per #389
 

### Notes
* More dynamic SQL generation in code instead of using external SQL
files. Those should only be used when they are not parametrized.
* The new function/table discovery mechanism: query for all functions in
the database, and match up those functions with the ones configured (if
any), plus adds all the rest of the un-declared ones if discovery mode
is on.
* During table and function discovery, the code generates a map of
`(PgSqlInfo, FunctionInfo)` (or table) tupples containing SQL needed to
get the tile.
* Auto-discovery mode is currently hidden - the discovery is on only
when no tables or functions are configured. TBD - how to configure it in
the future
* The new system allows for an easy way to auto-discover for the
specific schemas only, solving #47
* predictable order of table/function instantiation
* bounding boxes computed in parallel for all tables (when not
configured)
* proper identifier escaping
* test cleanup

fixes #378
fixes #466
fixes #65
fixes #389
2022-12-10 16:20:42 +02:00

23 lines
817 B
PL/PgSQL

DROP FUNCTION IF EXISTS public.function_zxy_query_test;
CREATE OR REPLACE FUNCTION public.function_zxy_query_test(z integer, x integer, y integer, query_params json) RETURNS bytea AS $$
DECLARE
mvt bytea;
BEGIN
RAISE DEBUG 'query_params: %', query_params;
IF (query_params->>'token')::varchar IS NULL THEN
RAISE EXCEPTION 'the `token` json parameter does not exist in `query_params`';
END IF;
SELECT INTO mvt ST_AsMVT(tile, 'public.function_zxy_query_test', 4096, 'geom') FROM (
SELECT
ST_AsMVTGeom(ST_Transform(ST_CurveToLine(geom), 3857), ST_TileEnvelope(z, x, y), 4096, 64, true) AS geom
FROM public.table_source
WHERE geom && ST_Transform(ST_TileEnvelope(z, x, y), 4326)
) as tile WHERE geom IS NOT NULL;
RETURN mvt;
END
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;