Move ne_50m data up one level in admin

osm2vectortiles.tm2source/data.yml

@@ -431,12 +431,8 @@ Layer:
             WHERE z(!scale_denominator!) = 0
             UNION ALL
             SELECT osm_id, geometry, admin_level, disputed, maritime
-            FROM admin_z1
-            WHERE z(!scale_denominator!) = 1
-            UNION ALL
-            SELECT osm_id, geometry, admin_level, disputed, maritime
-            FROM admin_z2
-            WHERE z(!scale_denominator!) = 2
+            FROM admin_z1toz2
+            WHERE z(!scale_denominator!) BETWEEN 1 AND 2
             UNION ALL
             SELECT osm_id, geometry, admin_level, disputed, maritime
             FROM admin_z3

src/import-sql/layers/admin.sql

@@ -2,26 +2,14 @@ CREATE OR REPLACE VIEW admin_z0 AS
     SELECT 0 AS osm_id, geom AS geometry, 2 AS admin_level, 0 AS disputed, 0 AS maritime
     FROM ne_110m_admin_0_boundary_lines_land;
 
-CREATE OR REPLACE VIEW admin_z1 AS
+CREATE OR REPLACE VIEW admin_z1toz2 AS
     SELECT 0 AS osm_id, geom AS geometry, 2 AS admin_level, 0 AS disputed, 0 AS maritime
-    FROM ne_110m_admin_0_boundary_lines_land
+    FROM ne_50m_admin_0_boundary_lines_land
     UNION ALL
     SELECT 0 AS osm_id, geom AS geometry, 4 AS admin_level, 0 AS disputed, 0 AS maritime
     FROM ne_50m_admin_1_states_provinces_lines
     WHERE scalerank = 2;
 
-CREATE OR REPLACE VIEW admin_z2 AS
-    SELECT 0 AS osm_id, geom AS geometry, 2 AS admin_level, 0 AS disputed, 0 AS maritime
-    FROM ne_110m_admin_0_boundary_lines_land
-    UNION ALL
-    SELECT id AS osm_id, geometry, admin_level, 0 AS disputed, maritime
-    FROM osm_admin_linestring
-    WHERE maritime = 1 AND admin_level = 2
-    UNION ALL
-    SELECT 0 AS osm_id, geom AS geometry, 4 AS admin_level, 0 AS disputed, 0 AS maritime
-    FROM ne_10m_admin_1_states_provinces_lines_shp
-    WHERE scalerank = 2;
-
 CREATE OR REPLACE VIEW admin_z3 AS
     SELECT 0 AS osm_id, geom AS geometry, 2 AS admin_level, 0 AS disputed, 0 AS maritime
     FROM ne_50m_admin_0_boundary_lines_land
@@ -69,9 +57,7 @@ CREATE OR REPLACE VIEW admin_z7toz14 AS
 CREATE OR REPLACE VIEW admin_layer AS (
     SELECT osm_id FROM admin_z0
     UNION
-    SELECT osm_id FROM admin_z1
-    UNION
-    SELECT osm_id FROM admin_z2
+    SELECT osm_id FROM admin_z1toz2
     UNION
     SELECT osm_id FROM admin_z3
     UNION