python正则表达式匹配sql语句中的表名

能够从sql语句中匹配表名，表的简称。使用的是python的正则表达式匹配的，本想做一个和plsql类似的工具，还没搞完整，先记录一下

# -*- coding: UTF-8 -*-


import re


keylist=['ACCESS','ADD','ALL','ALTER','AND','ANY','AS','ASC','AUDIT','BETWEEN','BY','CHAR','CHECK','CLUSTER','COLUMN','COMMENT','COMPRESS','CONNECT','CREATE','CURRENT','DATE','DECIMAL','DEFAULT','DELETE','DESC','DISTINCT','DROP','ELSE','EXCLUSIVE','EXISTS','FILE','FLOAT','FOR','FROM','GRANT','GROUP','HAVING','IDENTIFIED','IMMEDIATE','IN','INCREMENT','INDEX','INITIAL','INSERT','INTEGER','INTERSECT','INTO','IS','LEVEL','LIKE','LOCK','LONG','MAXEXTENTS','MINUS','MLSLABEL','MODE','MODIFY','NOAUDIT','NOCOMPRESS','NOT','NOWAIT','NULL','NUMBER','OF','OFFLINE','ON','ONLINE','OPTION','OR','ORDER','P','CTFREE','PRIOR','PRIVILEGES','PUBLIC','RAW','RENAME','RESOURCE','REVOKE','ROW','ROWID','ROWNUM','ROWS','SELECT','SESSION','SET','SHARE','SIZE','SMALLINT','START','SUCCESSFUL','SYNONYM','SYSDATE','TABLE','THEN','TO','TRIGGER','UID','UNION','UNIQUE','UPDATE','USER','VALIDATE','VALUES','VARCHAR','VARCHAR2','VIEW','WHENEVER','WHERE','WITH']


#sq3string = r"(\b[rRbB])?'''[^'\\]*((\\.|'(?!''))[^'\\]*)*(''')?"
sq3string = r"(\b[rRbB])?'[^'\\]*((\\.|'(?!''))[^'\\]*)*?(')?"      #倒数第二个？是为了最小匹配
sqs1 = r"(\b[rRbB])?"
sqs2 = r"A((?!table).)+B"    # 匹配排除table
selectmatch = r"(?!')*\bfrom\b\s+\b(?P<table_name>\w+)\b\s+\b(?P<table_sn>\w+)\b(?!')*"  #匹配select语句中的表名和表名的简写
insertmatch = r"(?!')*\binsert\b\s+\binto\b\s+\b(?P<table_name>\w+)\b\s+\b(?P<table_sn>\w+)\b(?!')*"  #匹配insert语句中的表名和表名的简写
updatematch = r"(?!')*\bupdate\b\s+\b(?P<table_name>\w+)\b\s+\b(?P<table_sn>\w+)(?!')+"  #匹配insert语句中的表名和表名的简写


#chars="select 'from tt we ,d f'*,t able from dual T where sfsf"
selectchars = "select *,'select * from tab3 T3 where T3.s' from tab1 T where a='select * from tab2 T2 where T2.s'"
insertchars = "insert into tab1 T1 (as) values (t,2,_)"
updatechars = "update tab1 t set df='update tab2 sdf set mm=1'"
#print(''.join([i+'|' for i in keylist])[0:-1])


##chars = selectchars
##
### 下面是去掉语句中的字符串，因为字符串可能含有sql语句
##sqloutstr = re.finditer(sq3string, chars, re.S)
##slt = [i for i in sqloutstr]
##slt.reverse()
##if sqloutstr:
##    for match in slt:
##        pl = match.span()
##        chars = chars[:pl[0]]+chars[pl[1]:]
##print(chars)
##
##mstr = selectmatch
##prog = re.compile(mstr, re.S|re.IGNORECASE)
##
##m1 = prog.match(chars)
##
##if m1:
##    print('m1.string',m1.string)
##    print('匹配到:',chars[m1.start():m1.end()])
##m = prog.search(chars)
##if m:
##    print('m',m.groupdict().items())
##    for key, value in m.groupdict().items():
##        print('key, value',key, value)


selectprog = re.compile(selectmatch, re.S|re.IGNORECASE)
updateprog = re.compile(updatematch, re.S|re.IGNORECASE)
inserprog = re.compile(insertmatch, re.S|re.IGNORECASE)


def delSqlStr(sqlstr):
    sqloutstr = re.finditer(sq3string, sqlstr, re.S)
    slt = [i for i in sqloutstr]
    slt.reverse()
    if sqloutstr:
        for match in slt:
            pl = match.span()
            sqlstr = sqlstr[:pl[0]]+sqlstr[pl[1]:]
    return sqlstr


def getSelectTBN(sqlstr):
    """ 返回select语句的 表名,表名简写"""
    TabName = None
    shortTabName = None
    m = selectprog.search(sqlstr)
    if m:
        for key, value in m.groupdict().items():
            if key == 'table_sn':
                shortTabName = value
            if key == 'table_name':
                TabName = value
    #print('getSelectTBN  TabName=',TabName, 'shortTabName=',shortTabName)
    return TabName,shortTabName
def getUpdateTBN(sqlstr):
    """ 返回select语句的 表名,表名简写"""
    TabName = None
    shortTabName = None
    m = updateprog.search(sqlstr)
    if m:
        for key, value in m.groupdict().items():
            if key == 'table_sn':
                shortTabName = value
            if key == 'table_name':
                TabName = value
    #print('getUpdateTBN  TabName=',TabName, 'shortTabName=',shortTabName)
    return TabName,shortTabName
def getInsertTBN(sqlstr):
    """ 返回select语句的 表名,表名简写"""
    TabName = None
    shortTabName = None
    m = inserprog.search(sqlstr)
    if m:
        for key, value in m.groupdict().items():
            if key == 'table_sn':
                shortTabName = value
            if key == 'table_name':
                TabName = value
    #print('getInsertTBN  TabName=',TabName, 'shortTabName=',shortTabName)
    return TabName,shortTabName


def getTabNameShortName(sqlstr):
    tmpsqlstr = delSqlStr(sqlstr)
    TabName = None
    shortTabName = None
    TabName,shortTabName = getSelectTBN(tmpsqlstr)
    if TabName:
        return TabName,shortTabName
    TabName,shortTabName = getUpdateTBN(tmpsqlstr)
    if TabName:
        return TabName,shortTabName
    TabName,shortTabName = getInsertTBN(tmpsqlstr)
    if TabName:
        return TabName,shortTabName


chars = "select * from tab1 T1 where T1.name='ssd'"
print(chars)
print(getTabNameShortName(chars))
chars = "update Tab2 T id=12,name='xiaoxiao'"
print(chars)
print(getTabNameShortName(chars))
chars = "insert into tab3 t3 values(13,'dada')"
print(chars)
print(getTabNameShortName(chars))