test.mml

# Normal YAML highlighting:
_parts:
srid:&srid "3857"
 # YAML comment
world:&world
--180
extents:&extents
extent:*world
srs-name:*srid
scale:1
interactivity:false
Layer:
-id: water-lines-low-zoom
geometry: linestring
geometry2:"string"
Datasource:
<<:*osm2pgsql
 table: |-
 -- Highlighting the table SQL by including PostgreSQL highlighting:
 (SELECT
 way,
 -- SQL comment
 waterway,
 CASE WHEN tags->'intermittent' IN ('yes')
 OR tags->'seasonal' IN ('yes', 'spring', 'summer', 'autumn', 'winter', 'wet_season', 'dry_season')
 THEN 'yes' ELSE 'no' END AS int_intermittent
 FROM planet_osm_line
 WHERE waterway = 'river'
 ) AS water_lines_low_zoom
properties:
minzoom:8 # number
maxzoom:11 # number