[英]Need regex expression to get only Tably name and primary key in python
May this question is silly, but i am not able to generate the regex expression to fetch table Name and PRIMARY KEY. 可能这个问题很愚蠢,但是我无法生成正则表达式来获取表名和主键。
CREATE TABLE 'dhcpr_dhcprelayinterface' (
'vrId' integer default 0,
'ifName' string ,
PRIMARY KEY(ifName,vrId),
FOREIGN KEY (vrId) REFERENCES 'vr_vr'(vrId) ON DELETE CASCADE ON UPDATE CASCADE);
I am using: begin = re.compile(r"CREATE TABLE[ \\"]*([^ \\"]+)[ \\"]*[(]([^/;]+)[/;]",re.IGNORECASE)
to fetch all table name and data. 我正在使用:
begin = re.compile(r"CREATE TABLE[ \\"]*([^ \\"]+)[ \\"]*[(]([^/;]+)[/;]",re.IGNORECASE)
以获取所有表名和数据。
But i would need data only with table name and PRIMARY KEY. 但是我只需要带有表名和PRIMARY KEY的数据。
Expected Output: 预期产量:
dhcpr_dhcprelayinterface
PRIMARY KEY(ifName,vrId)
This solution takes care of some issues you seem not worried about (but which are good to worry about), eg, SQLite allows you to write escaped '
as ''
, and there may be any number of spaces, even newlines, between CREATE
and TABLE
, and between PRIMARY
, KEY
, and (
: 此解决方案解决了您似乎不担心(但值得担心)的一些问题,例如,SQLite允许您将转义的
'
编写为''
,并且CREATE
和CREATE
之间可以有任意数量的空格,甚至是换行符。 TABLE
以及PRIMARY
, KEY
和(
:之间
s = """\
CREATE TABLE 'dhcpr_dhcprelayinterface' (
'vrId' integer default 0,
'ifName' string ,
PRIMARY KEY(ifName,vrId),
FOREIGN KEY (vrId) REFERENCES 'vr_vr'(vrId)
ON DELETE CASCADE ON UPDATE CASCADE);
"""
pattern = """
CREATE \s+ TABLE \s+
'((?:[^']|'')*)' # allows escaped single quote
.+ # stuff between table name and primary key
(PRIMARY \s+ KEY\s? \([^)]*\))
"""
mo = re.search(pattern, s, re.IGNORECASE | re.VERBOSE | re.DOTALL)
print(mo.groups())
Output: 输出:
('dhcpr_dhcprelayinterface', 'PRIMARY KEY(ifName,vrId)')
I'm sure you can solve it with regular expressions or sqlparse
, but here is a "fun" way of approaching the problem just for educational purposes - using sqlite3
in memory database - actually create the table and get the table_name
from the sqlite_master
internal table and primary key columns from the PRAGMA table_info
: 我敢肯定您可以使用正则表达式或
sqlparse
来解决它,但这是一种仅出于教育目的解决问题的“有趣”方法- 在内存数据库中使用sqlite3
实际创建表并从sqlite_master
内部表获取table_name
和PRAGMA table_info
主键列:
import sqlite3
query = """
CREATE TABLE 'dhcpr_dhcprelayinterface' (
'vrId' integer default 0,
'ifName' string ,
PRIMARY KEY(ifName,vrId),
FOREIGN KEY (vrId) REFERENCES 'vr_vr'(vrId) ON DELETE CASCADE ON UPDATE CASCADE);
"""
db = sqlite3.connect(":memory:")
cursor = db.cursor()
cursor.execute(query)
db.commit()
# get table name
cursor.execute("select name from sqlite_master where type = 'table'")
table_name = cursor.fetchone()[0]
print(table_name)
# get primary key columns
cursor.execute("PRAGMA table_info(%s);" % table_name)
pk_columns = [row[1] for row in cursor.fetchall()[::-1]]
print(pk_columns)
Prints: 印刷品:
dhcpr_dhcprelayinterface
['ifName', 'vrId']
You can use this to just get the table name and primary key. 您可以使用它来获取表名和主键。
begin = re.compile(r"CREATE TABLE[ ']*([^ ']+)[ ']*[(][^/;]+(PRIMARY KEY.*),[^/;]+;$", re.IGNORECASE)
begin.findall(YOUR_STR)
Outputs: 输出:
In [1]: a = """CREATE TABLE 'dhcpr_dhcprelayinterface' (
...: 'vrId' integer default 0,
...: 'ifName' string ,
...: PRIMARY KEY(ifName,vrId),
...: FOREIGN KEY (vrId) REFERENCES 'vr_vr'(vrId) ON DELETE CASCADE ON
UPDATE CASCADE);"""
In [2]: begin = re.compile(r"CREATE TABLE[ ']*([^ ']+)[ ']*[(][^/;]+(PRIMARY KEY.*),[^/;]+;$", re.IGNORECASE)
In [3]: begin.findall(a)
Out[3]: [('dhcpr_dhcprelayinterface', 'PRIMARY KEY(ifName,vrId)')]
The following was tested using python2.7: 使用python2.7测试了以下内容:
>>> table_string = """
... CREATE TABLE 'dhcpr_dhcprelayinterface' (
... 'vrId' integer default 0,
... 'ifName' string ,
... PRIMARY KEY(ifName,vrId),
... FOREIGN KEY (vrId) REFERENCES 'vr_vr'(vrId) ON DELETE CASCADE ON UPDATE CASCAD
E);"""
>>> p = r'CREATE TABLE\s+\'([^\']+)[\s\S]+PRIMARY KEY\(([^,]+),([^\)]+)\)'
>>> re.findall(p,table_string)
[('dhcpr_dhcprelayinterface', 'ifName', 'vrId')]
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.