SQL - LOWER() Function

The SQL Lower() function is used to convert all the letters of a string into lower-case letters.

It accepts a string value as a parameter and returns a new String by converting all the letters of the a String into lowercase. If this String contains special characters or numeric values, the output will remain unchanged by this function.

If any argument passed to this function is a NULL value, it returns NULL.

Syntax

This syntax uses the LOWER function with a set of uppercase letters (string) −

LOWER(String);

We can use the SQL LOWER() function with SQL table column names −

SELECT LOWER(Column_Name) AS LOWERFunction FROM Table_Name;

Parameters

  • str − It is a string which changes the character into lower case.

Return value

This function returns the lower case of the given string.

Example

The following SELECT query displays the characters String in lowercase in the output.

SELECT LOWER('B, A, N, U') AS LowerFunction;

Output

Following is the output of the above query −

+---------------+
| LowerFunction |
+---------------+
| b, a, n, u    |
+---------------+

Example

The following SELECT query converts all characters of the following uppercase string to the lowercase.

SELECT LOWER('TUTORIALSPOINT IS A ONLINE LEARNING PLATFORM') AS LOWERFunction;

Output

The above SQL query produces the following output −

+----------------------------------------------+
| LOWERFunction                                |
+----------------------------------------------+
| tutorialspoint is a online learning platform |
+----------------------------------------------+

Example

The following SELECT query converts the capital letters into the small letters(lowercase).

SELECT LOWER('My Name IS Chaitali') AS LowerFuction;

Output

On executing the above query, it will produce the following output −

+---------------------+
| LowerFuction        |
+---------------------+
| my name is chaitali |
+---------------------+

Example

The following SELECT query cannot change the characters of string because the LOWER function cannot change the symbols and integers of a string in SQL. So it displays the same.

SELECT LOWER('@2#567$%^&') AS LOWERFuction;

Output

On executing the above query, it will produce the following output −

+--------------+
| LOWERFuction |
+--------------+
| @2#567$%^&   |
+--------------+

Example

You can pass the table column as an argument to the LOWER() function to convert the character or string into a LOWER Function. Assume we have created a table with the name Customers using the CREATE statement as follows −

create table CUSTOMERS(
   ID INT NOT NULL, 
   NAME VARCHAR(15) NOT NULL, 
   AGE INT NOT NULL, 
   ADDRESS CHAR(25), 
   SALARY DECIMAL(10, 4), PRIMARY KEY(ID));

Now let's insert seven records into the customers table using the INSERT statement as follows:−

insert INTO CUSTOMERS(ID, NAME, AGE, ADDRESS, SALARY) VALUES(1, 'Ramesh', 32, 'Ahmedabad', 2000.00);
insert INTO CUSTOMERS(ID, NAME, AGE, ADDRESS, SALARY) VALUES(2, 'Khilan', 25, 'Delhi', 1500.00);
insert INTO CUSTOMERS(ID, NAME, AGE, ADDRESS, SALARY) VALUES(3, 'kaushik', 23, 'Kota', 2000.00);
insert INTO CUSTOMERS(ID, NAME, AGE, ADDRESS, SALARY) VALUES(4, 'Chaitali', 25, 'Mumbai', 6500.00);
insert INTO CUSTOMERS(ID, NAME, AGE, ADDRESS, SALARY) VALUES(5, 'Hardik', 27, 'Bhopal', 8500.00);
insert INTO CUSTOMERS(ID, NAME, AGE, ADDRESS, SALARY) VALUES(6, 'Komal', 22, 'MP', 4500.00);
insert INTO CUSTOMERS(ID, NAME, AGE, ADDRESS, SALARY) VALUES(7, 'Muffy', 24, 'Indore', 10000.00);

The following SELECT query uses the LOWER function with the Name column of the above CUSTOMERS table −

SELECT Name, LOWER(Name) AS LOWER_Name FROM CUSTOMERS;

Output

After executing the above statement, it produces the following output −

+----------+------------+
| Name     | LOWER_Name |
+----------+------------+
| Ramesh   | ramesh     |
| Khilan   | khilan     |
| kaushik  | kaushik    |
| Chaitali | chaitali   |
| Hardik   | hardik     |
| Komal    | komal      |
| Muffy    | muffy      |
+----------+------------+

Example

The following SELECT query uses the LOWER function with the NAME, ADDRESS column of the above CUSTOMERS table.

SELECT Name, LOWER(Name), Address, LOWER(Address) AS LowerFunction FROM CUSTOMERS;

Output

After executing the above statement, it produces the following output −

+----------+-------------+-----------+---------------+
| Name     | LOWER(Name) | Address   | LowerFunction |
+----------+-------------+-----------+---------------+
| Ramesh   | ramesh      | Ahmedabad | ahmedabad     |
| Khilan   | khilan      | Delhi     | delhi         |
| kaushik  | kaushik     | Kota      | kota          |
| Chaitali | chaitali    | Mumbai    | mumbai        |
| Hardik   | hardik      | Bhopal    | bhopal        |
| Komal    | komal       | MP        | mp            |
| Muffy    | muffy       | Indore    | indore        |
+----------+-------------+-----------+---------------+
sql-string-functions.htm
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