Question

我有一个sql select（sel =“ sql select text”），其中变量定义为：var_name

select  ... from (
select  ... from ( 
select  ... from  table1
where session_started between  toDateTime(:DatumOd) and toDateTime(:DatumDo)
and session_id in (select distinct ...  from table2
    where   session_start>=toDateTime('2019-01-01 10:11:12') and session_module=:channel
            and session_start between  toDateTime(:DatumOd) and toDateTime(:DatumDo)
            and ( domain_name in (:domain) or 'All domains' in (:domain) )
            and (technology in (:technology) or 'All' in (:technology))
            and (CASE when session_principal_role='Self care' then agent_name else session_principal_role end in  (:application) 
            or 'All' in (:application) )  )
order by session_id desc , execution_id desc, step_started desc, step_id desc)
) where step_type=:step_type and ...

变量以“：”开头，并以括号或空格结尾。我必须用$ {var_name}替换每个：var_name。

目前，我正在使用： re.sub（r“：（\ w +）”，r“ $ {\ 1}”，sel）给出：

select  ... from (
select  ... from ( 
select  ... from  table1
where session_started between  toDateTime(${DatumOd}) and toDateTime(${DatumDo})
and session_id in (select distinct ...  from table2
    where   session_start>=toDateTime('2019-01-01 10${11}${12}') and session_module=${channel}
            and session_start between  toDateTime(${DatumOd}) and toDateTime(${DatumDo})
            and ( domain_name in (${domain}) or 'All domains' in (${domain}) )
            and (technology in (${technology}) or 'All' in (${technology}))
            and (CASE when session_principal_role='Self care' then agent_name else session_principal_role end in  (${application}) 
            or 'All' in (${application}) )  )
order by session_id desc , execution_id desc, step_started desc, step_id desc)
) where step_type=${step_type} and ...

除了日期常量2019-01-01 10:11:12之外，其他所有方法都运行良好。由于其中包含“：”字符，其余字符将被识别为变量名。

仅当“：”字符后的下一个字符为字母时，才应替换。

该怎么做？

Answer 1

您可以使用此正则表达式，它使用积极的前瞻性来确保仅选择空格或)后跟的变量

:(\w+)(?=[ )\n]|$)

Demo

查看此Python代码，

import re

s = '''select  ... from (
select  ... from ( 
select  ... from  table1
where session_started between  toDateTime(:DatumOd) and toDateTime(:DatumDo)
and session_id in (select distinct ...  from table2
    where   session_start>=toDateTime('2019-01-01 10:11:12') and session_module=:channel
            and session_start between  toDateTime(:DatumOd) and toDateTime(:DatumDo)
            and ( domain_name in (:domain) or 'All domains' in (:domain) )
            and (technology in (:technology) or 'All' in (:technology))
            and (CASE when session_principal_role='Self care' then agent_name else session_principal_role end in  (:application) 
            or 'All' in (:application) )  )
order by session_id desc , execution_id desc, step_started desc, step_id desc)
) where step_type=:step_type and ...:DatumOd
:DatumOd'''

print(re.sub(r':(\w+)(?=[ )\n]|$)', r'${\1}',s))

仅打印预期的变量，忽略日期中的冒号

select  ... from (
select  ... from (
select  ... from  table1
where session_started between  toDateTime(${DatumOd}) and toDateTime(${DatumDo})
and session_id in (select distinct ...  from table2
    where   session_start>=toDateTime('2019-01-01 10:11:12') and session_module=${channel}
            and session_start between  toDateTime(${DatumOd}) and toDateTime(${DatumDo})
            and ( domain_name in (${domain}) or 'All domains' in (${domain}) )
            and (technology in (${technology}) or 'All' in (${technology}))
            and (CASE when session_principal_role='Self care' then agent_name else session_principal_role end in  (${application})
            or 'All' in (${application}) )  )
order by session_id desc , execution_id desc, step_started desc, step_id desc)
) where step_type=${step_type} and ...${DatumOd}
${DatumOd}

Answer 2

您可以尝试以下模式：'\W:(\w+)'，以便仅在冒号不跟随 word 字符的情况下选择冒号后的某物。它适用于该示例，但我不确定是否足以满足一般要求。

Answer 3

根据您的要求，您可以使用

s = re.sub(r'\B:([^\W\d_]\w*)', r'${\1}', s)

请参见regex demo。

详细信息

\B:-一个:，其前面没有单词char（或位于字符串开头）
([^\W\d_]\w*)-组1（替换模式中为\1）：
- [^\W\d_]-任何字母
- \w*-任意0+个字母，数字，下划线。

注意：如果要只匹配ASCII字母和数字，并且使用的是Python 3.x，请使用re.A或re.ASCII标志：

s = re.sub(r'\B:([^\W\d_]\w*)', r'${\1}', s, flags=re.A)

Python demo：

import re
s = "select  ... from (\r\nselect  ... from ( \r\nselect  ... from  table1\r\nwhere session_started between  toDateTime(:DatumOd) and toDateTime(:DatumDo)\r\nand session_id in (select distinct ...  from table2\r\n    where   session_start>=toDateTime('2019-01-01 10:11:12') and session_module=:channel\r\n            and session_start between  toDateTime(:DatumOd) and toDateTime(:DatumDo)\r\n            and ( domain_name in (:domain) or 'All domains' in (:domain) )\r\n            and (technology in (:technology) or 'All' in (:technology))\r\n            and (CASE when session_principal_role='Self care' then agent_name else session_principal_role end in  (:application) \r\n            or 'All' in (:application) )  )\r\norder by session_id desc , execution_id desc, step_started desc, step_id desc)\r\n) where step_type=:step_type and ..."
s = re.sub(r'\B:([^\W\d_]\w*)', r'${\1}', s, flags=re.A)
print(s)

输出：

select  ... from (
select  ... from ( 
select  ... from  table1
where session_started between  toDateTime(${DatumOd}) and toDateTime(${DatumDo})
and session_id in (select distinct ...  from table2
    where   session_start>=toDateTime('2019-01-01 10:11:12') and session_module=${channel}
            and session_start between  toDateTime(${DatumOd}) and toDateTime(${DatumDo})
            and ( domain_name in (${domain}) or 'All domains' in (${domain}) )
            and (technology in (${technology}) or 'All' in (${technology}))
            and (CASE when session_principal_role='Self care' then agent_name else session_principal_role end in  (${application}) 
            or 'All' in (${application}) )  )
order by session_id desc , execution_id desc, step_started desc, step_id desc)
) where step_type=${step_type} and ...

python regex替换所有以“：”开头的单词的出现，下一个字符为字母

3 个答案: