將SQL解析成層級結果來分析它

Question

有沒有可以解析SQL查詢（PostgreSQL類）的任何庫（可以在Python中使用），並給我一個結構化的表示形式？有sqlparse，但這不允許我輕鬆地找出（說）查詢正在使用的表。我只需要支持SELECT查詢，但其中一些可能非常複雜。

Answer 1

select_parser.py自帶pyparsing的示例將爲您提供語句的ParseResults數據結構。下面是嵌入式測試情況：

select * from xyzzy where z > 100 
select * from xyzzy where z > 100 order by zz 
select * from xyzzy 
select z.* from xyzzy 
select a, b from test_table where 1=1 and b='yes' 
select a, b from test_table where 1=1 and b in (select bb from foo) 
select z.a, b from test_table where 1=1 and b in (select bb from foo) 
select z.a, b from test_table where 1=1 and b in (select bb from foo) order by b,c desc,d 
select z.a, b from test_table left join test2_table where 1=1 and b in (select bb from foo) 
select a, db.table.b as BBB from db.table where 1=1 and BBB='yes' 
select a, db.table.b as BBB from test_table,db.table where 1=1 and BBB='yes' 
select a, db.table.b as BBB from test_table,db.table where 1=1 and BBB='yes' limit 50 

結果被構造成在輸入語句的不同組件，以及類似的對象屬性的命名的字段可以被訪問（result.table：'XYZZY'，result.where_expr：['z', '>', '100']等）。以下是前3個的測試結果：

select * from xyzzy where z > 100 
['SELECT', ['*'], 'FROM', 'xyzzy', 'WHERE', ['z', '>', '100']] 
- columns: ['*'] 
- from: ['xyzzy'] 
- table: ['xyzzy'] 
- where_expr: ['z', '>', '100'] 


select * from xyzzy where z > 100 order by zz 
['SELECT', ['*'], 'FROM', 'xyzzy', 'WHERE', ['z', '>', '100'], 'ORDER', 'BY', [['zz']]] 
- columns: ['*'] 
- from: ['xyzzy'] 
- order_by_terms: [['zz']] 
    [0]: 
    ['zz'] 
    - order_key: zz 
- table: ['xyzzy'] 
- where_expr: ['z', '>', '100'] 


select * from xyzzy 
['SELECT', ['*'], 'FROM', 'xyzzy'] 
- columns: ['*'] 
- from: ['xyzzy'] 
- table: ['xyzzy'] 

它被寫入到SQL方言SQLite的，但適應Postgres的不應該是太可怕了。