Usage of substr function in oracle

The substr() function extracts a substring of a string. The syntax is: substr(str, start, [length]). Usage example: Extract the 4 characters starting from the 3rd character from 'Hello World': SELECT substr('Hello World', 3, 4) FROM dual; Result: 'llo'.

Usage of substr() function in Oracle

The substr() function is used to extract substrings from strings . The syntax is as follows:

substr(str, start, [length])

Where:

• str: The string from which the substring is to be extracted.
• start: Extract the starting position of the substring, counting from 1.
• length(optional): The length of the substring to be extracted. If omitted, everything from the starting position to the end of the string is extracted.

Usage example

SELECT substr('Hello World', 3, 4) FROM dual;

Output:

llo 

Example description:

• This query extracts a 4-character substring starting from the 3rd character ('l') from the string 'Hello World'.
• The result substring is "llo".

Other usage examples:

• Extract the first character of the string:

  SELECT substr('Oracle', 1, 1) FROM dual;

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• Extract the last few characters of the string:

  SELECT substr('Database', -3) FROM dual;

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• Extract the substring of the specified length:

  SELECT substr('Programming', 1, 8) FROM dual;

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Note:

• start parameter must be greater than or equal to 1.
• length parameter must be greater than or equal to 0.
• If start length > string length, only the characters from start to the end of the string will be extracted.
• If start or length is negative, NULL will be returned.

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