oracle replace string

Oracle is a powerful database management system that is very convenient to use. In database management, string replacement is a common operation. In this article, we will discuss string replacement operations in Oracle.

Replacing a string means replacing a certain character or a group of characters in a string with another character or a group of characters. In Oracle, there are several ways to perform string replacement operations, including SQL functions and PL/SQL programs.

SQL functions:

Oracle provides many built-in SQL functions that can be used to perform string replacement operations. The following are some commonly used SQL functions:

1. REPLACE function

The REPLACE function is used to replace all occurrences of a character or a group of characters in a string with another A character or group of characters.

Syntax: REPLACE(string1, search_string, replacement_string)

Among them, string1 is the string to be replaced, search_string is the string to be found, and replacement_string is the character used to replace the search string. string.

Example:

SELECT REPLACE('December 31, 2000', 'Year', '/') AS DATE_STR FROM DUAL;

Output: 2000/12 Month 31

2. TRANSLATE function

The TRANSLATE function is used to convert a character in a string to another character or to delete a character.

Syntax: TRANSLATE(string1, from_string, to_string)

Among them, string1 is the string to be replaced, from_string is the character to be replaced, and to_string is the character used to replace the search character.

Example:

SELECT TRANSLATE('December 31, 2000', 'Year and Day', '//') AS DATE_STR FROM DUAL;

Output: 2000 //December 31//

PL/SQL program:

In addition to SQL functions, Oracle also provides the PL/SQL program language to perform string replacement operations. The following are some PL/SQL programs:

1. DBMS_PIPE.PACK_MESSAGE function

The DBMS_PIPE.PACK_MESSAGE function can be used to replace characters in a string with another character.

Syntax: DBMS_PIPE.PACK_MESSAGE(msg, pattern_list, replacement_list)

Among them, msg is the string to be replaced, pattern_list is a character list containing the characters to be replaced, and replacement_list is another A character list containing the characters to use to replace the characters.

Example:

DECLARE
msg VARCHAR2(20) := 'December 31, 2000';
BEGIN
DBMS_PIPE.PACK_MESSAGE(msg, 'Year' , '/');
DBMS_OUTPUT.PUT_LINE(msg);
END;

Output: December 31, 2000

2. REGEXP_REPLACE function

The REGEXP_REPLACE function is a regular expression function that can be used to find and replace matching subcharacters in a string.

Syntax: REGEXP_REPLACE(source_string, pattern, replace_string)

Among them, source_string is the string to be replaced, pattern is the regular expression to be found, and replace_string is used to replace the regular expression match. String.

Example:

SELECT REGEXP_REPLACE('December 31, 2000', 'Year', '/') AS DATE_STR FROM DUAL;

Output: 2000/12 Month 31

Summary:

In Oracle, string replacement can use SQL functions or PL/SQL programs. The REPLACE function and TRANSLATE function are commonly used string replacement functions in SQL functions, while the DBMS_PIPE.PACK_MESSAGE function and REGEXP_REPLACE function are commonly used string replacement functions in PL/SQL programs. Using these functions and procedures, you can easily perform string replacement operations in Oracle and save time and effort.

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