Document jsonpath .** accessor with nesting level filter

It appears that some variants of .** jsonpath accessor are undocumented.  In
particular undocumented variants are:

 .**{level}
 .**{lower_level to upper_level}
 .**{lower_level to last}

This commit adds missing documentation for them.

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 8c5df6f0bb0829ea5dddbe943b91ea1483a5412e..fae137439843bdfbd2f5c01118c238e475c45303 100644 (file)
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -807,6 +807,30 @@ SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @> '{"tags": ["qu
        
       
      
+     
+      
+       
+        .**{level}
+       
+       
+        .**{lower_level to
+        upper_level}
+       
+       
+        .**{lower_level to
+        last}
+       
+      
+      
+       
+        Same as .**, but with filter over nesting
+        level of JSON hierarchy.  Levels are specified as integers.
+        Zero level corresponds to current object.  This is a
+        PostgreSQL extension of the SQL/JSON
+        standard.
+       
+      
+