我有一个存储过程，使用UTL函数将CSV数据插入到oracle表中。我难以理解的部分是在插入目标表之前必须使用regexp_substr。我在各种网站上查看了regexp_substr，但仍然没有完全掌握如何将其应用于此特定导入程序的概念。
例如，假设我们有以下几行代码：
V_EMPNO := REGEXP_SUBSTR(V_LINE, '[^,]+', 1, 1);
V_ENAME := REGEXP_SUBSTR(V_LINE, '[^,]+', 1, 2);
我遇到的问题是，有人可以向我解释这条线路的逻辑是如何工作的吗？我有一个包含75个字段的CSV文件和目标表，所以当然这只是一个抽样，我知道我已经将这部分写得很长。我假设字符串的最后一部分只是行号，所以我不断递增它。
我的另一个问题是，我应该继续将所有记录定义为变量，并在导入的所有字段上单独执行regexp_substr吗？
答案 0 :(得分：3)
您可以使用以下逻辑而不是regexp_substr检查以下代码：
CREATE OR REPLACE PROCEDURE Import_Emp_File (P_FILENAME IN VARCHAR2,
o_msg OUT VARCHAR2)
IS
Infile UTL_FILE.File_Type;
Linebuf VARCHAR2 (4000);
V_Getstring VARCHAR2 (100);
-- Field Values Array
TYPE Fieldvalue IS TABLE OF VARCHAR2 (100)
INDEX BY BINARY_INTEGER;
Field_Position Fieldvalue;
Total_Rec_Count NUMBER := 0;
Total_Rec_Processed NUMBER := 0;
BEGIN
Infile := UTL_FILE.Fopen ('YOUR_DIRECTORY', P_FILENAME, 'R');
LOOP
---
UTL_FILE.Get_Line (Infile, Linebuf);
-- adding extra pipe in end of line to read all fields
Linebuf := Linebuf || '|';
-- Suppose the file is containing Six delimited strings with pipe (|)
FOR I IN 1 .. 6
LOOP
Field_Position (I) :=
Plsql_Delimited_String.Getstring (Linebuf,
I,
FALSE,
'|');
END LOOP;
BEGIN
Total_Rec_Count := Total_Rec_Count + 1;
-- an example table
INSERT INTO EMP (EMPLOYEE_NUMBER,
FIRST_NAME,
LAST_NAME,
DATE_OF_JOIN,
EMP_TYPE,
DATE_OF_REGN)
VALUES (field_position (1),
field_position (2),
field_position (3),
field_position (4),
field_position (5),
field_position (6));
Total_Rec_Processed := Total_Rec_Processed + 1;
EXCEPTION
WHEN OTHERS
THEN
-- ignoring error during database insertion
NULL;
END;
END LOOP;
IF UTL_FILE.is_open (infile)
THEN
UTL_FILE.Fclose (Infile);
END IF;
EXCEPTION
WHEN NO_DATA_FOUND
THEN
IF UTL_FILE.is_open (infile)
THEN
UTL_FILE.Fclose (Infile);
END IF;
IF total_rec_processed > 0
THEN
COMMIT;
END IF;
WHEN OTHERS
THEN
IF UTL_FILE.is_open (infile)
THEN
UTL_FILE.Fclose (Infile);
END IF;
o_msg := SQLERRM;
END;
/
还共享上述过程中使用的分隔字符串实用程序包，首先执行以下脚本，然后创建如上所示的过程：
CREATE OR REPLACE PACKAGE plsql_Delimited_String
IS
FUNCTION Counter (Source_string IN VARCHAR2,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER;
PROCEDURE PutString (Source_string IN OUT VARCHAR2,
String_to_add IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',');
PROCEDURE PutNumber (Source_string IN OUT VARCHAR2,
number_to_add IN NUMBER,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',');
PROCEDURE PutDate (Source_string IN OUT VARCHAR2,
Date_to_add IN DATE,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',');
FUNCTION GetString (Source_string IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN VARCHAR2;
FUNCTION GetNumber (Source_string IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER;
FUNCTION GetDate (Source_string IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN DATE;
FUNCTION Locate (Source_string IN VARCHAR2,
Search_String IN VARCHAR2,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER;
FUNCTION Locate (Source_string IN VARCHAR2,
Search_date IN DATE,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER;
FUNCTION Locate (Source_string IN VARCHAR2,
Search_number IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER;
END plsql_Delimited_String;
/
CREATE OR REPLACE PACKAGE BODY plsql_Delimited_String
IS
FUNCTION Counter (Source_string IN VARCHAR2,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER
IS
iModifier PLS_INTEGER := 0;
iOldSize PLS_INTEGER := LENGTH (Source_string);
BEGIN
IF Unterminated
THEN
iModifier := 1;
END IF;
RETURN (iOldSize - LENGTH (REPLACE (Source_string, Delimiter)))
+ iModifier;
END Counter;
PROCEDURE PutString (Source_string IN OUT VARCHAR2,
String_to_add IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
IS
iStrLen PLS_INTEGER := LENGTH (Source_String);
iStrFragLen PLS_INTEGER := LENGTH (String_to_add);
iPtrStart PLS_INTEGER := 0;
iPtrEnd PLS_INTEGER := 0;
vcSepBuffer VARCHAR2 (2000);
iCounter PLS_INTEGER;
BEGIN
-- 1. is the string Zero Length?
IF iStrLen = 0
THEN
IF Field_Position > 1
THEN
FOR iCounter IN 2 .. Field_Position
LOOP
vcSepBuffer := vcSepBuffer || Delimiter;
END LOOP;
END IF;
Source_string := vcSepBuffer || String_to_add;
IF NOT UnTerminated
THEN
Source_string := Source_String || Delimiter;
iStrLen := LENGTH (Source_string);
END IF;
ELSE
-- 2. Cope with unterminated strings
IF UnTerminated
THEN
Source_string := Source_string || Delimiter;
END IF;
-- 3. Locate the nth-1 separator
IF Field_Position > 1
THEN
LOOP
iPtrStart :=
(INSTR (Source_string || vcSepBuffer,
Delimiter,
1,
Field_Position - 1)
- 1)
+ LENGTH (Delimiter);
EXIT WHEN iPtrStart > 0;
vcSepBuffer := vcSepBuffer || Delimiter;
END LOOP;
IF vcSepBuffer IS NOT NULL
THEN
iPtrEnd := iStrLen;
ELSE
iPtrEnd :=
INSTR (Source_string,
Delimiter,
1,
Field_Position);
IF iPtrEnd = 0
THEN
iPtrEnd := iStrLen;
END IF;
END IF;
ELSE
iPtrStart := 0;
iPtrEnd :=
INSTR (Source_string,
Delimiter,
1,
Field_Position);
IF iPtrEnd = 0
THEN
iPtrEnd := iStrLen;
END IF;
END IF;
-- 3. Rebuild the string
Source_string :=
SUBSTR (Source_string, 1, iPtrStart)
|| vcSepBuffer
|| String_to_add
|| Delimiter
|| SUBSTR (Source_string, iPtrEnd + LENGTH (Delimiter));
-- 4. Sort out termination
IF UnTerminated
THEN
Source_string :=
SUBSTR (Source_String,
1,
(LENGTH (Source_string) - LENGTH (Delimiter)));
END IF;
END IF;
END PutString;
PROCEDURE PutNumber (Source_string IN OUT VARCHAR2,
number_to_add IN NUMBER,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
IS
BEGIN
-- 1. Just do datatype conversions and call the varchar2 varsion of put..
plsql_Delimited_String.PutString (Source_string,
TO_CHAR (number_to_add),
Field_position,
UnTerminated,
Delimiter);
END PutNumber;
PROCEDURE PutDate (Source_string IN OUT VARCHAR2,
Date_to_add IN DATE,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
IS
BEGIN
-- 1. Just do datatype conversions and call the varchar2 varsion of put..
plsql_Delimited_String.PutString (
Source_string,
TO_CHAR (date_to_add, 'DD-MON-YYYY HH24:MI:SS'),
Field_position,
UnTerminated,
Delimiter);
END PutDate;
FUNCTION GetString (Source_string IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN VARCHAR2
IS
iPtrEnd PLS_INTEGER := 0;
iPtrStart PLS_INTEGER := 0;
vcSourceStrCopy VARCHAR2 (2000) := Source_string;
BEGIN
IF UnTerminated
THEN
vcSourceStrCopy := vcSourceStrCopy || Delimiter;
END IF;
IF Field_Position > 1
THEN
iPtrStart :=
INSTR (vcSourceStrCopy,
Delimiter,
1,
Field_Position - 1)
+ LENGTH (Delimiter);
ELSE
iPtrStart := 1;
END IF;
iPtrEnd :=
INSTR (vcSourceStrCopy,
Delimiter,
1,
Field_Position);
RETURN SUBSTR (vcSourceStrCopy, iPtrStart, (iPtrEnd - iPtrStart));
END GetString; /* String Version */
FUNCTION GetNumber (Source_string IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER
IS
iRc PLS_INTEGER;
BEGIN
RETURN TO_NUMBER (GetString (Source_string,
Field_Position,
UnTerminated,
Delimiter));
END GetNumber; /* Number Version */
FUNCTION GetDate (Source_string IN VARCHAR2,
Field_position IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN DATE
IS
BEGIN
RETURN TO_DATE (GetString (Source_string,
Field_Position,
UnTerminated,
Delimiter), 'DD-MON-YYYY HH24:MI:SS');
END GetDate; /* Date Version */
FUNCTION Locate (Source_string IN VARCHAR2,
Search_String IN VARCHAR2,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER
IS
iHit PLS_INTEGER := 0;
iCounter PLS_INTEGER;
vcCompare VARCHAR2 (2000);
BEGIN
FOR iCounter IN 1 .. Counter (Source_String, UnTerminated, Delimiter)
LOOP
IF GetString (Source_String,
iCounter,
UnTerminated,
Delimiter) = Search_String
THEN
iHit := iCounter;
EXIT;
END IF;
END LOOP;
RETURN iHit;
END Locate;
FUNCTION Locate (Source_string IN VARCHAR2,
Search_date IN DATE,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER
IS
BEGIN
RETURN Locate (Source_string,
TO_CHAR (Search_date, 'DD-MON-YYYY HH24:MI:SS'),
UnTerminated,
Delimiter);
END Locate; /* Date Version */
FUNCTION Locate (Source_string IN VARCHAR2,
Search_number IN NUMBER,
UnTerminated IN BOOLEAN DEFAULT FALSE,
Delimiter IN VARCHAR2 DEFAULT ',')
RETURN NUMBER
IS
BEGIN
RETURN Locate (Source_string,
TO_CHAR (Search_number),
UnTerminated,
Delimiter);
END Locate; /* Number Version */
END; /* Body */
/