oracle PL/SQL 中 LOOP 中 CLOB 数据类型的串联
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Concatenation of CLOB datatypes in a LOOP in PL/SQL
提问by Tunde
I am trying to concatenate clobs in a PL/SQL loop and it has been returning null whilst when using DBMS_OUTPUT prints out the loop values and when executing each result of the clobs gives an output as well.
我试图在 PL/SQL 循环中连接 clobs 并且它一直返回 null 而当使用 DBMS_OUTPUT 打印出循环值并且在执行 clobs 的每个结果时也会给出输出。
The system is meant to execute an already stored SQL in a table based on the report name passed into it. This particular report has many report names; hence the concatenation of each of the reports. The arguments passed are the report name, version of the report you're interested in, the kind of separator you want, and an argument list for the unknowns in the SQL if any. There are also two main types of SQL; 1 that needs the table_name be replaced with a temp table_name and another that needs an ID be appended to a table_name in the SQL.
该系统旨在根据传入的报告名称执行表中已存储的 SQL。这个特定的报告有很多报告名称；因此，每个报告的串联。传递的参数是报告名称、您感兴趣的报告版本、所需的分隔符类型以及 SQL 中未知数的参数列表（如果有）。还有两种主要的 SQL 类型；1 需要将 table_name 替换为临时 table_name，另一个需要将 ID 附加到 SQL 中的 table_name。
please find below the code for the REPREF1 function.
请在下面找到 REPREF1 函数的代码。
CREATE OR REPLACE FUNCTION REPREF1(P_VER IN VARCHAR2 DEFAULT 'LATEST',
P_SEPARATOR IN VARCHAR2 DEFAULT ', ',
P_ARGLIST IN VAR DEFAULT NULL) RETURN CLOB IS
L_CLOB CLOB;
FUNCTION GET_CLOB(P_REPNAM IN VARCHAR2,
P_VER IN VARCHAR2 DEFAULT 'LATEST',
P_SEPARATOR IN VARCHAR2 DEFAULT ', ',
P_ARGLIST IN VAR DEFAULT NULL) RETURN CLOB IS
---------------------------------------------------------------------------------
-- TITLE - GET_CLOB beta - b.0 DATE 2010Mar12
--
-- DESCRIPTION - A function that return a report based on the report name put in
--
-- USAGE - select get_clob(p_repnam,p_ver, p_separator, var(varay(val_1,...val_n), varay(val_1,...val_n))) FROM dual
-----------------------------------------------------------------------------------------------------------------------------
V_SQL VARCHAR2(32767);
L_RESULT CLOB;
V_TITLE VARCHAR2(4000);
V_REPDATE VARCHAR2(30);
V_CNT NUMBER(2);
V_NUMARG NUMBER(3);
V_CDCRU NUMBER(3);
V_BCNT NUMBER(3);
V_NEWTABDAT VARCHAR2(30);
V_NEWTABLIN VARCHAR2(30);
L_COLLIST VARAY;
V_VER VARCHAR2(6);
N PLS_INTEGER;
V_CNTTAB NUMBER(3);
-- EXEC_SQL_CLOB
FUNCTION EXEC_SQL_CLOB(P_SQL IN VARCHAR2,
P_NUMARG IN NUMBER,
P_COLLIST IN VARAY DEFAULT NULL,
P_ARGLIST IN VARAY DEFAULT NULL,
P_SEPARATOR IN VARCHAR2 DEFAULT '') RETURN CLOB IS
------------------------------------------------------------------------------------------------------
-- TITLE - EXEC_SQL_CLOB beta - b.0 DATE 2010Mar22
--
-- DESCRIPTION - A function that returns a clob value after executing the sql query that is passed into it
--
-- USAGE - select exec_sql_clob(p_sql, p_numarg, var(varay(val_1, val_2,...val_n), varay(val_1, val_2,...val_n))) FROM dual
---------------------------------------------------------------------------------------------------------------
L_CUR INTEGER DEFAULT DBMS_SQL.OPEN_CURSOR;
L_STATUS INTEGER;
V_COL VARCHAR2(4000);
L_RESULT CLOB;
L_COLCNT NUMBER DEFAULT 0;
L_SEPARATOR VARCHAR2(10) DEFAULT '';
V_NUMARG NUMBER(3);
BEGIN
-- parse the query for the report
DBMS_SQL.PARSE(L_CUR, P_SQL, DBMS_SQL.NATIVE);
-- whilst it is not more than 255 per line
FOR I IN 1 .. 255
LOOP
BEGIN
-- define each column in the select list
DBMS_SQL.DEFINE_COLUMN(L_CUR, I, V_COL, 2000);
L_COLCNT := I;
EXCEPTION
WHEN OTHERS THEN
IF (SQLCODE = -1007) THEN
EXIT;
ELSE
RAISE;
END IF;
END;
END LOOP;
-- If query has no bind variables
IF (P_ARGLIST IS NULL) THEN
IF (P_NUMARG = 0) THEN
-- Execute the query in the cursor
L_STATUS := DBMS_SQL.EXECUTE(L_CUR);
LOOP
-- Exit loop when fetch is complete
EXIT WHEN(DBMS_SQL.FETCH_ROWS(L_CUR) <= 0);
L_SEPARATOR := '';
FOR I IN 1 .. L_COLCNT
LOOP
DBMS_SQL.COLUMN_VALUE(L_CUR, I, V_COL);
L_RESULT := L_RESULT || L_SEPARATOR || V_COL;
L_RESULT := REPLACE(REPLACE(L_RESULT, CHR(13) || CHR(10), ' '), CHR(10), ' ');
L_SEPARATOR := P_SEPARATOR;
END LOOP;
L_RESULT := L_RESULT || CHR(13);
END LOOP;
ELSE
RAISE_APPLICATION_ERROR(-20011, ' INCORRECT NUMBER OF ARGUMENTS PASSED IN LIST ');
END IF;
-- Query has bind variables
ELSE
-- Check if the numarg passed is the same has stored in the table
SELECT NUMARG
INTO V_NUMARG
FROM REPVER
WHERE REPCODE = P_SQL;
-- If number of arguments is greater than 0
IF (V_NUMARG > 0) THEN
-- Check if the number of arguments are the same
IF (P_NUMARG = V_NUMARG) THEN
-- Replace the bind variables in the query
FOR J IN 1 .. P_ARGLIST.COUNT
LOOP
DBMS_SQL.BIND_VARIABLE(L_CUR, P_COLLIST(J), P_ARGLIST(J));
END LOOP;
-- Execute the query in the cursor
L_STATUS := DBMS_SQL.EXECUTE(L_CUR);
LOOP
-- Exit loop when fetch is complete
EXIT WHEN(DBMS_SQL.FETCH_ROWS(L_CUR) <= 0);
L_SEPARATOR := '';
FOR I IN 1 .. L_COLCNT
LOOP
DBMS_SQL.COLUMN_VALUE(L_CUR, I, V_COL);
L_RESULT := L_RESULT || L_SEPARATOR || V_COL;
L_RESULT := REPLACE(REPLACE(L_RESULT, CHR(13) || CHR(10), ' '), CHR(10), ' ');
L_SEPARATOR := P_SEPARATOR;
END LOOP;
L_RESULT := L_RESULT || CHR(13);
END LOOP;
ELSE
RAISE_APPLICATION_ERROR(-20011, ' INCORRECT NUMBER OF ARGUMENTS PASSED IN LIST ');
END IF;
ELSE
-- If the number of argument is equal to 0
IF (P_NUMARG = 0) THEN
-- Execute the query in the cursor
L_STATUS := DBMS_SQL.EXECUTE(L_CUR);
LOOP
-- Exit loop when fetch is complete
EXIT WHEN(DBMS_SQL.FETCH_ROWS(L_CUR) <= 0);
L_SEPARATOR := '';
FOR I IN 1 .. L_COLCNT
LOOP
DBMS_SQL.COLUMN_VALUE(L_CUR, I, V_COL);
L_RESULT := L_RESULT || L_SEPARATOR || V_COL;
L_RESULT := REPLACE(REPLACE(L_RESULT, CHR(13) || CHR(10), ' '), CHR(10), ' ');
L_SEPARATOR := P_SEPARATOR;
END LOOP;
L_RESULT := L_RESULT || CHR(13);
END LOOP;
ELSE
RAISE_APPLICATION_ERROR(-20011, ' INCORRECT NUMBER OF ARGUMENTS PASSED IN LIST ');
END IF;
END IF;
END IF;
-- Close cursor
DBMS_SQL.CLOSE_CURSOR(L_CUR);
RETURN L_RESULT;
END EXEC_SQL_CLOB;
BEGIN
-- Check if the version entered is null or latest
IF (P_VER IS NULL)
OR (UPPER(P_VER) = UPPER('LATEST')) THEN
SELECT MAX(VER)
INTO V_VER
FROM REPORT B, REPVER R
WHERE UPPER(REPNAM) = UPPER(P_REPNAM)
AND B.REPREF = R.REPREF;
ELSE
V_VER := P_VER;
END IF;
-- Check if the repname and version entered exists
SELECT COUNT(*)
INTO V_CNT
FROM REPORT B, REPVER R
WHERE UPPER(REPNAM) = UPPER(P_REPNAM)
AND VER = V_VER
AND B.REPREF = R.REPREF;
IF (V_CNT > 0) THEN
-- Store the SQL statement, title and number of arguments of the report name passed.
SELECT REPCODE, REPTITLE, NUMARG, COLLIST
INTO V_SQL, V_TITLE, V_NUMARG, L_COLLIST
FROM REPVER R, REPORT B
WHERE UPPER(REPNAM) = UPPER(P_REPNAM)
AND B.REPREF = R.REPREF
AND VER = V_VER;
V_REPDATE := TO_CHAR(SYSDATE, 'YYYY-MM-DD HH24:MI');
L_RESULT := V_TITLE || ' (' || P_REPNAM || ' version ' || V_VER || ') generated ' || V_REPDATE || CHR(13) || CHR(13);
-- Check for some specific type of queries
SELECT COUNT(*)
INTO V_CDCRU
FROM REPVER R, REPORT B
WHERE CTDDATA = 'Y'
AND UPPER(REPNAM) = UPPER(P_REPNAM)
AND B.REPREF = R.REPREF
AND VER = V_VER;
SELECT COUNT(*)
INTO V_BCNT
FROM REPVER R, BODCREPS B
WHERE BENLIST = 'Y'
AND UPPER(REPNAM) = UPPER(P_REPNAM)
AND B.REPREF = R.REPREF
AND VER = V_VER;
IF (V_CDCRU > 0) THEN
V_NEWTABDATA := 'CT_' || 'DAT_' || P_ARGLIST(1) (P_ARGLIST(1).FIRST);
V_NEWTABLINK := 'CT_' || 'LIN_' || P_ARGLIST(1) (P_ARGLIST(1).FIRST);
-- Check if the tables exist
SELECT COUNT(*)
INTO V_CNTTAB
FROM ALL_TABLES
WHERE TABLE_NAME = V_NEWTABDAT
OR TABLE_NAME = V_NEWTABLIN
AND OWNER = 'SCOTT';
IF (V_CNTTAB > 0) THEN
V_SQL := UPPER(V_SQL);
V_SQL := REPLACE(V_SQL, 'CT_DAT_CRU', V_NEWTABDAT);
V_SQL := REPLACE(V_SQL, 'CT_LIN_CRU', V_NEWTABLIN);
ELSE
V_SQL := 'SELECT ''THE TABLE NOT CREATED YET''
FROM DUAL';
END IF;
END IF;
IF (V_BCNT > 0) THEN
V_SQL := UPPER(V_SQL);
V_SQL := REPLACE(V_SQL, 'LIST', P_ARGLIST(1) (P_ARGLIST(1).LAST));
END IF;
IF (P_ARGLIST IS NULL) THEN
-- execute the query
L_RESULT := L_RESULT || EXEC_SQL_CLOB(V_SQL, V_NUMARG, L_COLLIST, NULL, P_SEPARATOR);
ELSE
N := P_ARGLIST.COUNT;
-- execute the query
L_RESULT := L_RESULT || EXEC_SQL_CLOB(V_SQL, V_NUMARG, L_COLLIST, P_ARGLIST(N), P_SEPARATOR);
END IF;
RETURN L_RESULT;
ELSE
RAISE_APPLICATION_ERROR(-20012, P_REPNAM || ' or ' || P_VER || ' DOES NOT EXIST ');
END IF;
END GET_CLOB;
BEGIN
FOR I IN (SELECT REPNAM
FROM REPORT
WHERE REPREF NOT IN ('R01', 'R02', 'R03', 'R04'))
LOOP
SELECT CONCAT_CLOB(GET_CLOB(I.REPNAM, P_VER, P_SEPARATOR, P_ARGLIST))
INTO L_CLOB
FROM DUAL;
DBMS_OUTPUT.PUT_LINE(I.REPNAM);
-- DBMS_OUTPUT.PUT_LINE (COUNT(i.REPNAM));
END LOOP;
RETURN L_CLOB;
END REPREF1;
/
Cheers, Tunde
干杯，通德
Many thanks APC for making the code look better. @Robert, the last loop in the code returns null even with the CONCAT_CLOB aggregate function that concatenates clobs.
非常感谢 APC 让代码看起来更好。@Robert，即使使用连接 clobs 的 CONCAT_CLOB 聚合函数，代码中的最后一个循环也返回 null。
FOR I IN (SELECT REPNAM
FROM REPORT
WHERE REPREF NOT IN ('R01', 'R02', 'R03', 'R04'))
LOOP
SELECT CONCAT_CLOB(GET_CLOB(I.REPNAM, P_VER, P_SEPARATOR, P_ARGLIST))
INTO L_CLOB
FROM DUAL;
DBMS_OUTPUT.PUT_LINE(I.REPNAM);
END LOOP;
when I try this,
当我尝试这个时
FOR I IN (SELECT REPNAM
FROM REPORT
WHERE REPREF NOT IN ('R01', 'R02', 'R03', 'R04'))
LOOP
L_CLOB := L_CLOB || CHR(13) || GET_CLOB(I.REPNAM, P_VER, P_SEPARATOR, P_ARGLIST);
DBMS_OUTPUT.PUT_LINE(I.REPNAM);
END LOOP;
It also gives null; but this time the dbms output for the repnam are not complete.
它也给 null; 但这一次 repnam 的 dbms 输出不完整。
回答by Rene
Don't know about your code. Here is how it works for me: Whenever I create a function returning a clob value I do this:
不知道你的代码。这是它对我的工作方式：每当我创建一个返回 clob 值的函数时，我都会这样做：
function foo return clob is
l_clob clob;
begin
dbms_lob.createtemporary(lob_loc => l_clob, cache => true, dur => dbms_lob.call);
...
return l_clob;
end;
When concatenating values into a clob I use a function:
将值连接到 clob 时，我使用了一个函数：
procedure add_string_to_clob(p_lob in out nocopy clob
,p_string varchar2) is
begin
dbms_lob.writeappend(lob_loc => p_lob, amount => length(p_string), buffer => p_string);
end;
回答by Mahan
You have to use
你必须使用
dbms_lob.substr(your clob parameter,start position, length)
dbms_lob.substr(your clob parameter,start position, length)
e.g
例如
dbms_output('my clob value:' || dbms_lob.substr(your clob parameter,start position, length);
dbms_output('my clob value:' || dbms_lob.substr(your clob parameter,start position, length);
But you can print in a string max 4000 character, you can then use this in a looping function to print 4000 characters in each line.
但是您可以打印最多 4000 个字符的字符串，然后您可以在循环函数中使用它在每行中打印 4000 个字符。
