I am using Oracle SQL Developer and trying to export a table to a CSV file. Some of the fields are CLOB fields, and in many cases the entries are truncated when the export happens. I'm looking for a way to get the whole thing out, as my end goal is to not use Oracle here (I received an Oracle dump - which was loaded into an oracle db, but am using the data in another format so going via CSV as an intermediary).
If there are multiple solutions to this, given that it is a one time procedure for me, I don't mind the more hack-ish type solutions to more involved "do it right" solutions.
回答1:
if you have access to the file system on your database box you could do something like this:
CREATE OR REPLACE DIRECTORY documents AS 'C:\'; SET SERVEROUTPUT ON DECLARE l_file UTL_FILE.FILE_TYPE; l_clob CLOB; l_buffer VARCHAR2(32767); l_amount BINARY_INTEGER := 32767; l_pos INTEGER := 1; BEGIN SELECT col1 INTO l_clob FROM tab1 WHERE rownum = 1; l_file := UTL_FILE.fopen('DOCUMENTS', 'Sample2.txt', 'w', 32767); LOOP DBMS_LOB.read (l_clob, l_amount, l_pos, l_buffer); UTL_FILE.put(l_file, l_buffer); l_pos := l_pos + l_amount; END LOOP; EXCEPTION WHEN OTHERS THEN DBMS_OUTPUT.put_line(SQLERRM); UTL_FILE.fclose(l_file); END; /
You may also find this previous question about UTL_FILE useful. It addresses exporting to CSV. I have no idea or experience with how UTL_FILE handles CLOBs, however.
回答2:
You can use a Python script to take care of the export, the CLOBs won't get truncated:
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 = get_cursor() sql_filename ='your_query.sql'# Write your query there cursor = execute_sql_file(sql_filename, cursor,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
assuming by an Oracle dump you meant a .dmp (either from export or expdp), you're looking at a binary file. You'll need to import the dumpfile into an Oracle database and then export the data to plain text using UTL_FILE or other means.
回答4:
Here is a short yet general python script that does just this - dumping tables (with CLOB fields, among the rest) to a flat csv file: OraDump
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