sql - Need a query to insert 'level' into an adjacent list -

i have table so

id               node                  parentid 1                                        0 2                 b                        1 3                 c                        1 4                 d                        2 5                 e                        2 6                 f                        3 7                 g                        3 8                 h                        3  9                                        4 10                j                        4 11                k                        10 12                l                        11 

i need query generate 'level' field shows how many levels deep particular node is. example below

id               node                  parentid                  level 1                                        0                         1 2                 b                        1                         2 3                 c                        1                         2 4                 d                        2                         3 5                 e                        2                         3 6                 f                        3                         4 7                 g                        3                         4 8                 h                        3                         4  9                                        4                         5 10                j                        4                         5 11                k                        10                        6 12                l                        11                        7 

select id,        node,        parentid,        dense_rank() over(order parentid) level         table_name 

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