The following table shows the commonly used SQLite string functions that perform an operation on an input string and return a new string or a numeric value.
| Name | Description |
| SUBSTR | Extract and returns a substring with a predefined length starting at a specified position in a source string |
| TRIM | Return a copy of a string that has specified characters removed from the beginning and the end of a string. |
| LTRIM | Return a copy of a string that has specified characters removed from the beginning of a string. |
| RTRIM | Return a copy of a string that has specified characters removed from the end of a string. |
| LENGTH | Return the number of characters in a string or the number of bytes in a BLOB. |
| REPLACE | Return a copy of a string with each instance of a substring replaced by another substring. |
| UPPER | Return a copy of a string with all of the characters converted to uppercase. |
| LOWER | Return a copy of a string with all of the characters converted to lowercase. |
| INSTR | Find a substring in a string and returns an integer indicating the position of the first occurrence of the substring. |
| Concatenation Operator || | Concatenate two strings into a single string. |
INSTR
SELECT INSTR('SQLite String Functions','Functions') Position;
LENGTH
SELECT
LENGTH('SQLite');
LOWER
SELECT
LOWER('String Functions');

LTRIM
SELECT
LTRIM(' SQLite '),
LENGTH(' SQLite ') LengthBefore,
LENGTH(LTRIM(' SQLite ')) LengthAfter;

RTRIM
SELECT
RTRIM(' SQLite '),
LENGTH(' SQLite ') LengthBefore,
LENGTH(RTRIM(' SQLite ')) LengthAfter;
REPLACE
SELECT
REPLACE('These are string functions', 'These', 'Those');
SUBSTR
SELECT
SUBSTR('SQLite String Functions', 1, 6);

TRIM
SELECT
TRIM(' SQLite ');
UPPER
SELECT
UPPER('String Functions');
Concatenation Operator ||
This example shows how to concatenate two strings into a single string:
SELECT 'Concatenation ' || 'Operator';