LPAD

lpad(str, len[, pad])

Description

The LPAD function is used to perform left-side padding on a string. When the length of the given string str is less than the specified len, the LPAD function will pad the left side of str with the pad string until the total length of the new string equals len. If the length of str is already equal to or greater than len, the original string is returned. If len is less than 1, an empty string is returned. If the pad string is not specified, the default padding character is a space (' ').

Parameter Description

• str (required): The original string that needs left-side padding.
• len (required): The target length of the string.
• pad (optional): The string used for padding. The default value is a space character (' ').

Return Value

Returns a new string with a length of len, padded on the left side with the pad string.

Usage Example

1. Padding with a single character:

> SELECT lpad('hello', 7, '#');
##hello

2. Using the default padding character (space):

> SELECT lpad('world', 10);
      world

In this example, the length of the original string "world" is 5, and we need to pad it to 10 characters. Since the pad string is not specified, the LPAD function uses the default space character for padding, resulting in the new string " world".

3. Specify the padding string as a special character:

> SELECT lpad('!', 6, '@@');
@@@@@!

4. When len is less than 1, return an empty string:

> SELECT lpad('example', 0, '%');

In this example, the specified target length len is 0, and the LPAD function will return an empty string.