我有以下问题： 我有一个表Source_Data（实际上，有很多不同的源表），我需要将一些数据从它们导出到Result_Table中。对于每个源表，我都有一些返回数据的sql，需要将其转换为类似csv的字符串。
例如，Source_Data1表具有PK-ID，一些外键-A_ID，B_ID，CREATION_DATE日期和其他一些列。
我需要导出从Source_Data1表中选择数据的SQL查询结果，它通常返回主键，一些不为null的外键和一个也不为null的日期，并将其转换为类似于cvs的字符串，以后应另存为Clob。
CREATE TABLE Source_Data1 (
ID NUMBER(3) NOT NULL,
A_ID NUMBER(10) NOT NULL,
B_ID NUMBER(10) NOT NULL,
CREATION_DATE DATE NOT NULL,
some other columns );
我有SQL查询：
select ID, A_ID, B_ID, CREATION_DATE
from Source_Data1
where <expression>
基于此查询，我需要生成如下字符串：
'ID,A_ID,B_ID,CREATION_DATE
1,200,10,2018-03-01 00:00:00.0
7,202,11,2018-03-02 00:00:00.0
8,205,11,2018-03-02 00:00:00.0'
，我需要将它作为Clob保存到Result表中：
Insert into Result_Table (ID, SOURCE_NAME, DATA) values
(result_seq.nextval, 'Source_Data1', result of sqlquery 1);
许多源表都需要这样做。
我想知道是否有一些通用的方法？因为对于每个源表，我都有自己的sql查询，一组不同的选定列，以及手动生成此csv字符串，看起来不是很好。
谢谢您的建议。
答案 0 :(得分：0)
第1步应该是下载SQLcl，您可以通过“ SET SQLFORMAT CSV”和SPOOL轻松以CSV格式保存SQL select语句的输出，它会为您完成工作。因此，您可以使用它来遍历一堆表名/选择语句，假脱机，然后将它们的输出通过外壳脚本保存到目录中。
接下来，这是一个软件包，其中包含一堆文件实用程序，所有这些实用程序都可用于oracle DIRECTORY对象及其中的文件。使用此工具和一些PL / SQL，您可以轻松地将保存的文件拉到表中。可能会有更简便的方法来做您想做的事情，如果有的话，我希望能为其他人听到。这是一个要解决的大问题。
1）file_into_blob-将文件放入数据库
2）convert_blob_to_clob-转换为Clob
3）然后您可以将其插入表中。
包装规格
Create or replace package fileutils as
--
-- This procedure deletes a file, and depends on an Oracle DIRECTORY object being passed
--
Procedure delete_os_file (i_directory varchar2, i_filename varchar2);
--
-- This procedure moves and optionally renames a file,
-- and depends on an Oracle DIRECTORY object being passed
--
Procedure move_os_file ( i_source_directory in varchar2, i_source_file in varchar2, i_target_directory in varchar2, i_target_file in varchar2);
--
-- This procedure takes a blob variable and writes it to a file,
-- and depends on an Oracle DIRECTORY object being passed
--
Procedure blob_into_file (i_directory in varchar2, i_file_name in varchar2, i_blob in blob);
--
-- This procedure takes a file and uploads it into a blob variable
-- and depends on an Oracle DIRECTORY object being passed
--
Procedure file_into_blob(i_directory in varchar2, i_file_name in varchar2, o_blob out blob);
--
-- This procedure converts a clob to a blob
--
Procedure convert_clob_to_blob (i_clob in clob, o_blob out blob);
--
-- This procedure converts a blob to a clob
--
Procedure convert_blob_to_clob (i_blob in blob, o_clob out clob);
--
-- This one checks for file existence without Java
--
Function file_exists (i_directory in varchar2, i_filename in varchar2) return boolean;
--
-- Returns the basename of a filename
-- Works with Windows and UNIX pathnames
--
Function basename (i_filename in varchar2) return varchar2;
--
-- This takes a Base64 string and converts it to a binary BLOB
--
Procedure base64_string_to_blob (i_clob in clob, o_blob out blob);
Function base64_string_to_blob (i_clob in clob) return blob;
--
-- This takes a binary BLOB and converts it to a Base64 string
--
Procedure blob_to_base64_string (i_blob in blob, o_clob out clob);
Function blob_to_base64_string (i_blob in blob) return clob;
End fileutils;
/
Show error;
包装体
Set define off;
Create or replace package body fileutils as
Procedure delete_os_file (i_directory varchar2, i_filename varchar2)
is
Begin
utl_file.fremove(i_directory,i_filename);
End;
Procedure move_os_file
(
i_source_directory in varchar2,
i_source_file in varchar2,
i_target_directory in varchar2,
i_target_file in varchar2
)
is
srcdir varchar2(255) := upper(i_source_directory);
tgtdir varchar2(255) := upper(i_target_directory);
begin
--
-- NOTE: If you're getting the all-too-familiar
-- ORA-29292: file rename operation failed
-- and you're SURE that your directory names are correct,
-- and you're SURE that your privileges are correct, both at the
-- OS level, and within the database, there's one last thing that
-- can get you. I learned the hard way that this command will NOT
-- work successfully renaming a file from one filesystem to another,
-- at least when those filesystems are NFS mounted. That is all.
--
utl_file.frename(srcdir,i_source_file,tgtdir,i_target_file,TRUE);
end move_os_file;
Procedure blob_into_file (i_directory in varchar2, i_file_name in varchar2, i_blob in blob)
is
l_file utl_file.file_type;
l_buffer raw(32767);
l_amount binary_integer := 32767;
l_pos integer := 1;
i_blob_len integer;
Begin
i_blob_len := dbms_lob.getlength(i_blob);
l_pos:= 1;
-- Open the destination file.
l_file := utl_file.fopen(i_directory,i_file_name,'wb', 32767);
-- Read chunks of the BLOB and write them to the file
-- until complete.
while l_pos < i_blob_len loop
dbms_lob.read(i_blob, l_amount, l_pos, l_buffer);
utl_file.put_raw(l_file, l_buffer, TRUE);
l_pos := l_pos + l_amount;
end loop;
-- Close the file.
utl_file.fclose(l_file);
End blob_into_file;
Procedure file_into_blob(i_directory in varchar2, i_file_name in varchar2, o_blob out blob)
is
src_loc bfile := bfilename(i_directory, i_file_name);
Begin
-- Initialize the dest blob
o_blob := empty_blob();
-- Open source binary file from OS
dbms_lob.open(src_loc, dbms_lob.lob_readonly);
-- Create temporary LOB object
dbms_lob.createtemporary(
lob_loc => o_blob
, cache => true
, dur => dbms_lob.session
);
-- Open temporary lob
dbms_lob.open(o_blob, dbms_lob.lob_readwrite);
-- Load binary file into temporary LOB
dbms_lob.loadfromfile(
dest_lob => o_blob
, src_lob => src_loc
, amount => dbms_lob.getLength(src_loc));
-- Close lob objects
dbms_lob.close(o_blob);
dbms_lob.close(src_loc);
End file_into_blob;
Function basename (i_filename in varchar2) return varchar2
is
v_basename varchar2(1024);
Begin
--
-- If the regex's below don't match, then it's already at its base name
-- Return what was passed.
--
v_basename := i_filename;
if regexp_like(i_filename,'^.*\\') then
dbms_output.put_line('This is a Windows file');
v_basename := regexp_substr(i_filename,'[^\]*$');
dbms_output.put_line('Basename is : '||v_basename);
end if;
if regexp_like(i_filename,'^/') then
dbms_output.put_line('This is a UNIX file');
v_basename := regexp_substr(i_filename,'[^/]*$');
dbms_output.put_line('Basename is : '||v_basename);
end if;
return v_basename;
End basename;
Function file_exists (i_directory in varchar2, i_filename in varchar2) return boolean
is
v_exists boolean;
v_file_length number;
v_block_size number;
Begin
utl_file.fgetattr(upper(i_directory), i_filename, v_exists, v_file_length, v_block_size);
if (v_exists) then
dbms_output.put_line('File '||i_filename||' exists, '||v_file_length||' bytes');
else
dbms_output.put_line('File '||i_filename||' does not exist');
end if;
return v_exists;
end file_exists;
Procedure convert_clob_to_blob (i_clob in clob, o_blob out blob)
is
v_in pls_Integer := 1;
v_out pls_Integer := 1;
v_lang pls_Integer := 0;
v_warning pls_Integer := 0;
Begin
dbms_lob.createtemporary(o_blob,TRUE);
dbms_lob.converttoblob(o_blob,i_clob,DBMS_lob.getlength(i_clob),v_in,v_out,dbms_lob.default_csid,v_lang,v_warning);
End convert_clob_to_blob;
Procedure convert_blob_to_clob (i_blob in blob, o_clob out clob)
is
v_in pls_Integer := 1;
v_out pls_Integer := 1;
v_lang pls_Integer := 0;
v_warning pls_Integer := 0;
Begin
dbms_lob.createtemporary(o_clob,TRUE);
dbms_lob.converttoclob(o_clob,i_blob,DBMS_lob.getlength(i_blob),v_in,v_out,dbms_lob.default_csid,v_lang,v_warning);
End convert_blob_to_clob;
Procedure blob_to_base64_string (i_blob in blob, o_clob out clob)
is
v_out_cl clob;
file_len pls_integer;
modulo pls_integer;
pieces pls_integer;
amt binary_integer := 23808;
buf raw (32767);
buf_tx varchar2(32767);
pos pls_integer := 1;
filepos pls_integer := 1;
counter pls_integer := 1;
Begin
dbms_lob.createtemporary (v_out_cl, true, dbms_lob.call);
file_len := dbms_lob.getlength (i_blob);
modulo := mod (file_len, amt);
pieces := trunc (file_len / amt);
while (counter <= pieces) loop
dbms_lob.read (i_blob, amt, filepos, buf);
buf_tx:=utl_raw.cast_to_varchar2 (utl_encode.base64_encode (buf));
dbms_lob.writeappend (v_out_cl,length(buf_tx),buf_tx);
filepos := counter * amt + 1;
counter := counter + 1;
end loop;
if (modulo <> 0) THEN
dbms_lob.read (i_blob, modulo, filepos, buf);
buf_tx:=utl_raw.cast_to_varchar2 (utl_encode.base64_encode (buf));
dbms_lob.writeappend (v_out_cl,length(buf_tx),buf_tx);
end if;
o_clob := v_out_cl;
End blob_to_base64_string;
Function blob_to_base64_string (i_blob in blob) return clob
is
v_out_cl clob;
file_len pls_integer;
modulo pls_integer;
pieces pls_integer;
amt binary_integer := 23808;
buf raw (32767);
buf_tx varchar2(32767);
pos pls_integer := 1;
filepos pls_integer := 1;
counter pls_integer := 1;
Begin
dbms_lob.createtemporary (v_out_cl, true, dbms_lob.call);
file_len := dbms_lob.getlength (i_blob);
modulo := mod (file_len, amt);
pieces := trunc (file_len / amt);
while (counter <= pieces) loop
dbms_lob.read (i_blob, amt, filepos, buf);
buf_tx:=utl_raw.cast_to_varchar2 (utl_encode.base64_encode (buf));
dbms_lob.writeappend (v_out_cl,length(buf_tx),buf_tx);
filepos := counter * amt + 1;
counter := counter + 1;
end loop;
if (modulo <> 0) THEN
dbms_lob.read (i_blob, modulo, filepos, buf);
buf_tx:=utl_raw.cast_to_varchar2 (utl_encode.base64_encode (buf));
dbms_lob.writeappend (v_out_cl,length(buf_tx),buf_tx);
end if;
return v_out_cl;
End blob_to_base64_string;
Procedure base64_string_to_blob (i_clob in clob, o_blob out blob)
is
v_out_bl blob;
clob_size number;
pos number;
charBuff varchar2(32767);
dBuffer RAW(32767);
v_readSize_nr number;
v_line_nr number;
begin
dbms_lob.createTemporary (v_out_bl, true, dbms_lob.call);
v_line_nr:=greatest(65, instr(i_clob,chr(10)), instr(i_clob,chr(13)));
v_readSize_nr:= floor(32767/v_line_nr)*v_line_nr;
clob_size := dbms_lob.getLength(i_clob);
pos := 1;
while (pos < clob_size) loop
dbms_lob.read (i_clob, v_readSize_nr, pos, charBuff);
dBuffer := UTL_ENCODE.base64_decode (utl_raw.cast_to_raw(charBuff));
dbms_lob.writeAppend (v_out_bl,utl_raw.length(dBuffer),dBuffer);
pos := pos + v_readSize_nr;
end loop;
o_blob := v_out_bl;
end base64_string_to_blob;
Function base64_string_to_blob (i_clob in clob) return blob
is
v_out_bl blob;
clob_size number;
pos number;
charBuff varchar2(32767);
dBuffer RAW(32767);
v_readSize_nr number;
v_line_nr number;
begin
dbms_lob.createTemporary (v_out_bl, true, dbms_lob.call);
v_line_nr:=greatest(65, instr(i_clob,chr(10)), instr(i_clob,chr(13)));
v_readSize_nr:= floor(32767/v_line_nr)*v_line_nr;
clob_size := dbms_lob.getLength(i_clob);
pos := 1;
while (pos < clob_size) loop
dbms_lob.read (i_clob, v_readSize_nr, pos, charBuff);
dBuffer := UTL_ENCODE.base64_decode (utl_raw.cast_to_raw(charBuff));
dbms_lob.writeAppend (v_out_bl,utl_raw.length(dBuffer),dBuffer);
pos := pos + v_readSize_nr;
end loop;
return v_out_bl;
end base64_string_to_blob;
end fileutils;
/
Show error;
答案 1 :(得分：0)
我认为您可以使用LISTAGG函数
select listagg(ONE_LINE) WITHIN GROUP (ORDER BY ROW_NUM)
from (
select 'ID,A_ID,B_ID,CREATION_DATE' || CHR(10) as ONE_LINE,
-1 as ROW_NUM
from dual
union all
select ID ||','|| A_ID ||','|| B_ID ||','|| CREATION_DATE || CHR(10) as ONE_LINE,
ROWNUM as ROW_NUM
from Source_Data1
where <expression>
);
答案 2 :(得分：0)
以下代码将使用DATA_DUMP.SQL和函数DBMS_XSLPROCESSOR.READ2CLOB将表的CSV版本创建为CLOB行。
首先，在您的架构上安装DATA_PUMP过程。该程序是单个文件中的单个命令，您可以通过SQL * Plus运行它，也可以将其复制并粘贴到IDE中。
接下来，在服务器上创建一个目录以临时存储文件。现有的大多数实用程序都是用来创建文件的。与修改实用程序直接写入表相比，编写文件并将其作为CLOB读取要容易得多。
create or replace directory temp_dir as 'C:\temp';
然后，此PL / SQL块将读取和写入数据：
--Store a table as a single CSV clob.
--TODO: Delete the files from the server when done.
declare
v_clob clob;
begin
for tables in
(
--Query that returns the table names.
--(Doesn't have to be hard-coded, maybe a query on DBA_TABLES would help?)
select column_value table_name
from table(sys.odcivarchar2list('source_data'))
) loop
data_dump
(
query_in => 'select * from source_data1',
file_in => 'source_data1.csv',
directory_in => 'temp_dir',
nls_date_fmt_in => 'YYYY-MM-DD HH24:MI:SS',
delimiter_in => ',',
header_row_in => true
);
v_clob := dbms_xslprocessor.read2clob
(
flocation => 'TEMP_DIR',
fname => 'source_data1.csv'
);
insert into result_table (id, source_name, data) values
(result_seq.nextval, 'source_data1', v_clob);
--I wouldn't normally commit after each row, but when exporting large
--tables the script may run too long and there's a good chance of an
--error, so partial results may be helpful.
commit;
end loop;
end;
/
读取和写入CSV文件并不是一门科学，但并不是大多数人认为的那么简单。那里有99％的CSV程序无法处理数据中的逗号或添加标题行之类的问题。因此，最好是查找预先存在的代码，而不是编写自己的实用程序。