SQL - CHOOSE() Function

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The SQL CHOOSE() function is used to retrieve the item(or value) from the list of values. It accepts two parameters index and list of values(val1, val2, ...valn) and returns the item(or value) at the specified index from the list of values in the SQL server.

Note − The list value begins at index value 1; if the index value is zero, the CHOOSE() function returns NULL.

Syntax

Following is the syntax of the SQL CHOOSE() function −

CHOOSE ( index, val_1, val_2 [, val_n ] ) 

Parameters

• index − It is an integer value specifying the index value in the list.

• val_1 ... val_n − It is the list of comma-separated values with any datatype.

Return value

This function returns a item from the list at the specified index value.

Example

In the following example, we are using the SQL CHOOSE() function to retrieve the item( or value) from the current list of values 'Java', 'SQL', 'MySQL', 'JavaScript' at the specified index 2.

SELECT CHOOSE ( 2, 'Java', 'SQL', 'MySQL', 'JavaScript') AS Item;

Output

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

+-------+
| Item  |
+-------+
| SQL   |
+-------+

Example

You can also pass the list of numeric values to the SQL CHOOSE() function.

Following is another example of SQL CHOOSE() function to retrieve the item(or value) from the current numeric list '100, 200, 300, 4000, 500' at the specified index(or position) 4.

SELECT CHOOSE ( 4, 100, 200, 300, 400, 500) AS Item;

Output

Following is the output of the above statement −

+-------+
| Item  |
+-------+
| 400   |
+-------+

Example

If we pass the index argument value as zero to the function, this function returns a NULL value.

In this program, we are passing the index argument value as zero(0) to the SQL CHOOSE() function. Then, using this function, we are trying to retrieve the item(or value) from the current list ('Mango', 'Banana', 'Apple', 'Orange') at the specified index 0.

SELECT CHOOSE ( 0, 'Mango', 'Banana', 'Apple', 'Orange') AS Item;

Output

The above SQL statement produces the following output −

+-------+
| Item  |
+-------+
| NULL  |
+-------+

Example

If we pass an empty list(‘’) to the CHOOSE() function, this function returns an empty value for index 1, and a NULL value for the rest of all indexes.

SELECT CHOOSE ( 1, '') AS Item;
SELECT CHOOSE ( 2, '') AS Item;

Output

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

+-------+
| Item  |
+-------+
|       |
+-------+
+-------+
| Item  |
+-------+
| NULL  |
+-------+

Example

If the current list is NULL, the CHOOSE() function returns NULL.

SELECT CHOOSE ( 1, NULL) AS Item;

Output

Following is the output of the above query −

+-------+
| Item  |
+-------+
| NULL  |
+-------+

Example

You can also pass the table column as an argument to the SQL CHOOSE() function to retrieve the item(or value) from the content of the column. Assume we have created a table with the name Customer using the CREATE statement as follows −

CREATE TABLE CUSTOMERS(    
ID INT NOT NULL,    
NAME VARCHAR (20) NOT NULL,    
AGE INT NOT NULL,    
ADDRESS CHAR (25) ,    
SALARY DECIMAL (18, 2));

Now, let's insert some records in to the Customers table using the INSERT statement as shown below −

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 );

The following SQL query retrieves the item(or value) from the content of the column Salary in the Customers table −

SELECT ID, NAME, CHOOSE(1, SALARY) AS CUST_SALARY FROM CUSTOMERS;

Output

The above SQL query generate the following output −

+----+----------+---------------+
| ID | NAME     | CUST_SALARY   |
+----+----------+---------------+
|  1 | Ramesh   | 2000.00       |
|  2 | Khilan   | 1500.00       |
|  3 | kaushik  | 2000.00       |
|  4 | Chaitali | 6500.00       |
+----+----------+---------------+