我想将包含大型CLOB的查询结果导出到CSV文件.但是,一旦在CSV文件中导出,CLOB就会在大约4K个字符后被截断(即它们过早地以“……”结束).如何防止Oracle sql Developer在导出时截断CLOB？
您可以绕过Oracle sql Developer进行导出,例如您可以使用Python脚本来处理导出,以便CLOB不会被截断：
from __future__ import print_function
from __future__ import division
import time
import cx_Oracle
def get_cursor():
'''
Get a cursor to the database
'''
# https://stackoverflow.com/questions/24149138/cx-oracle-doesnt-connect-when-using-sid-instead-of-service-name-on-connection-s
# http://www.oracle.com/technetwork/articles/dsl/prez-python-queries-101587.html
ip = '' # E.g. '127.0.0.1'
port = '' # e.g. '3306'
sid = ''
dsnStr = cx_Oracle.makedsn(ip,port,sid)
username = '' # E.g. 'FRANCK'
password = '' # E.g. '123456'
db = cx_Oracle.connect(user=username,password=password,dsn=dsnStr)
cursor = db.cursor()
return cursor
def read_sql(filename):
'''
Read an sql file and return it as a string
'''
file = open(filename,'r')
return ' '.join(file.readlines()).replace(';','')
def execute_sql_file(filename,cursor,verbose = False,display_query = False):
'''
Execute an sql file and return the results
'''
sql = read_sql(filename)
if display_query: print(sql)
start = time.time()
if verbose: print('sql query started... ',end='')
cursor.execute(sql)
if verbose:
end = time.time()
print('sql query done. (took {0} seconds)'.format(end - start))
return cursor
def main():
'''
This is the main function
'''
# Demo:
cursor = oracle_db.get_cursor()
sql_filename = 'your_query.sql' # Write your query there
cursor = oracle_db.execute_sql_file(sql_filename,True)
result_filename = 'result.csv' # Will export your query result there
result_file = open(result_filename,'w')
delimiter = ','
for row in cursor:
for count,column in enumerate(row):
if count > 0: result_file.write(delimiter)
result_file.write(str(column))
result_file.write('\n')
result_file.close()
if __name__ == "__main__":
main()
#cProfile.run('main()') # if you want to do some profiling
