LTRIM

LTRIM(str [, trimStr])

Description

The LTRIM function is used to remove specified characters or spaces from the left side of the string str. If the trimStr parameter is not provided, all space characters on the left side of str are removed by default.

Parameter Description

• str (string): The original string to be processed.
• trimStr (string, optional): Specifies the set of characters to be removed from the left side of str.

Return Result

Returns the processed string.

Usage Example

1. Remove all spaces from the left side of the string:

SELECT 'X' || LTRIM('    HelloWorld    ') || 'X';
-- Result: XHelloWorld    X

2. Remove specific characters from the left side of the string:

SELECT LTRIM('HelloWorld', 'He');
-- Result: World

3. 删除字符串左侧的多个字符（字符集）：

```markdown
3. Delete multiple characters (character set) from the left side of the string:
```sql
SELECT LTRIM('!!!HelloWorld!!!', '!');
-- Result: HelloWorld

4. When trimStr is an empty string, str will not be modified:

SELECT LTRIM('Hello', '');
-- Result: Hello

5. If trimStr contains characters that do not exist in str, the LTRIM function will still remove the spaces on the left side of str:

SELECT LTRIM('Hello', 'abc');
-- Result: Hello

Notes

• When the trimStr parameter is empty or contains only spaces, the behavior of the LTRIM function is the same as the default behavior of the LTRIM function, which removes all spaces from the left side of the string.
• If the trimStr parameter contains non-printable characters or special characters, these characters will also be used to remove characters from the left side of str.