Back to Function Index

LOWER()

Overview

LOWER() converts all characters in a string to lowercase. It is the opposite of the UPPER() function. This function is useful for case-insensitive string comparisons, data normalization, and text formatting.

Function Format

LOWER(string)

Return Value

LOWER() returns a character string

Examples

LOWER("APPLES") = "apples"                    (all uppercase to lowercase)
LOWER("Apples and Oranges") = "apples and oranges"  (mixed case to lowercase)
LOWER("Hello World!") = "hello world!"        (preserves non-alphabetic characters)
LOWER("123") = "123"                         (numbers unchanged)
LOWER("") = ""                               (empty string)
LOWER(NULL) = NULL                           (NULL input)
LOWER("SQL") = "sql"                         (acronyms converted)

Notes

• Important behaviors:
  • Converts all uppercase letters to lowercase
  • Preserves lowercase letters
  • Preserves non-alphabetic characters
  • Returns NULL for NULL input
  • Returns empty string for empty string input
• Common use cases include:
  • Case-insensitive string comparisons
  • Data normalization
  • Text formatting
  • Search operations
  • Data cleaning
• The function can be used with:
  • String literals
  • String columns
  • String expressions
  • String functions
• This function is often used in combination with other string functions like UPPER(), TRIM(), and CONCAT() for more complex string manipulations.
• For case-insensitive comparisons, consider using LOWER() on both sides of the comparison.

See Also

• UPPER()
• TRIM()
• CONCAT()
• REPLACE()