Function source to dynamically load tiles from tables.

martin_dynamic_table_query.sql

CREATE OR REPLACE FUNCTION function_zxy_query(z integer, x integer, y integer, query_params json)
RETURNS bytea AS $$
DECLARE
  mvt bytea;
  table_name text;
  sql_query text;
BEGIN
  -- Extract the table name from query_params
  table_name := (query_params->>'table_name');

  -- Construct the SQL query dynamically using the extracted table name
  EXECUTE format('
    SELECT ST_AsMVT(tile, ''function_zxy_query'', 4096, ''geometry'')
    FROM (
      SELECT ST_AsMVTGeom(
          ST_Transform(ST_CurveToLine(geometry), 3857),
          ST_TileEnvelope(%L, %L, %L),
          4096, 64, true) AS geometry,
          jsonb_build_object(
            ''id'', properties->>''id''
          ) AS properties
      FROM %I
      WHERE geometry && ST_Transform(ST_TileEnvelope(%L, %L, %L), 4326)
    ) as tile
    WHERE geometry IS NOT NULL;
 ', z, x, y, table_name, z, x, y) INTO mvt;

  RETURN mvt;
END
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;