SQL - SELECT LAST

SELECT LAST is a concept or function often used to describe retrieving the last record or last row from a table in SQL. Although MS Access supports a LAST() function to directly fetch the last value from a column, this function is not universally supported across all SQL-based databases. Instead, in MySQL, PostgreSQL, Oracle, and SQL Server, there are alternative methods to get the last record in a table. 

In this article, we will learn how to get the last record in a Table. We are going to discuss four different ways to extract the latest information from a table in the database.

SQL - SELECT LAST

Retrieving the last record is a common requirement in many applications. Whether you’re dealing with log files, e-commerce transactions, or tracking user activity, you generally need the ability to query the latest data from a table. Since SELECT LAST() is not universally supported, we need to use other approaches to extract the last record efficiently.

Methods to Retrieve the Last Record in SQL

We will discuss four different methods to retrieve the last record from a table in an SQL database. The methods will vary based on the database you are working with. Before we discuss the methods to retrieve the last record, let’s create the Student_Information table and populate it with some sample data.

CREATE TABLE Student_Information (
    ID INT PRIMARY KEY,
    Age INT,
    Student_Name VARCHAR(50),
    Sex VARCHAR(10)
);

-- Inserting sample records
INSERT INTO Student_Information (ID, Age, Student_Name, Sex)
VALUES (1, 22, 'Harry', 'Male');

INSERT INTO Student_Information (ID, Age, Student_Name, Sex)
VALUES (2, 23, 'Vishal', 'Male');

INSERT INTO Student_Information (ID, Age, Student_Name, Sex)
VALUES (3, 20, 'Snehal', 'Female');

INSERT INTO Student_Information (ID, Age, Student_Name, Sex)
VALUES (4, 25, 'Ram', 'Male');

INSERT INTO Student_Information (ID, Age, Student_Name, Sex)
VALUES (5, 24, 'Hina', 'Female');

The Student_Information table now looks like this:

Method 1: Using the LAST() Function in MS Access

We can use the command FIRST() to extract the first entry of a particular column and LAST() to extract the last entry of a particular column in a Table. For more information visit First() and Last()Function in MS Access.

Syntax :

LAST(expression)

For example, say we want to  extract the last student name from the table "Student Information"

SELECT LAST(Student_name) AS Stud_Name 
FROM StudentInformation;

Output:

As we can see, the last student name "Hina" is extracted using the above query. But it is to be noted that SELECT LAST or LAST(expression) is only supported in MS Access. This statement doesn't support MYSQL, Oracle, PostgreSQL, etc. There are alternate ways as discussed below to perform the above operation in other versions of SQL like MYSQL, Oracle, PostgreSQL, etc.

Method 2: By Sorting the Data

We can use the ORDER BY statement and LIMIT clause to extract the last data. The basic idea is to sort the sort the table in descending order and then we will limit the number of rows to 1. In this way, we will get the output as the last row of the table. And then we can select the entry which we want to retrieve.

MYSQL syntax :

SELECT col_name(s) FROM Table_Name
ORDER BY appr_col_name DESC
LIMIT 1;

col_name(s): The name of the column(s).
appr_col_name: Appropriate column name to perform ORDER BY.

Oracle syntax :

SELECT col_name(s) FROM Table_Name
ORDER BY appr_col_name DESC
WHERE ROWNUM <= 1;

col_name(s): The name of the column(s).
appr_col_name: Appropriate column name to perform ORDER BY.

Output :

It is important to note that in order to perform sorting, the column needs to be chosen properly.  For example, if we choose "ORDER BY Student_name DESC" then it will alphabetically sort the table on the basis of names. So, the row containing "Vishal" will come at the top, but the row having "Vishal" as entry is not the last row of the table. Also, we can't use the column "Age"  to perform ORDER BY as shown below:

Hence, it is mandatory to use the column ID or any column which is unique and sequentially increasing with every record in the table.

Method 3: By using Subquery and AGGREGATE MAX()

 Subquery is nothing but a query inside another query that maintains a parent-child relationship. The inner query will execute first followed by the outer query. Here, in this method, the basic idea is to get the maximum ID using aggregate function MAX and then select the student name associated with that maximum ID. In this way, we can extract the last student's name from the table.

SELECT col_name(s) FROM Table_Name
WHERE appr_col_name = (
        SELECT MAX(appr_col_name)
        FROM Table_Name
);

col_name(s): The name of the column(s).
appr_col_name: Appropriate column name. For example ID.

Output :

Method 4: By Comparative or Relative Approach

In this method also, we are going to use a subquery. The basic idea is to filter out the rows and to check that no such row exists having higher ID values than the row we are going to extract. This will help in getting the row with maximum ID and hence we can retrieve the last information. It is a complex query and is an iterative approach in which we are going to use the NOT EXISTS statement. This method will take more time to execute if there are more records in the table.

SELECT col_name(s) FROM Table_Name t1
WHERE NOT EXISTS(
    SELECT * FROM Table_Name t2
    WHERE t2.appr_col_name > t1.appr_col_name
);

col_name(s): The name of the column(s).
appr_col_name: Appropriate column name. For example ID.

Output :

Conclusion

In this article, we explored several methods for retrieving the last record from a SQL table, including the use of the LAST() function (in MS Access), sorting with ORDER BY and LIMIT, using the MAX() function in a subquery, and employing the NOT EXISTS approach.

Depending on your SQL database system (MySQL, PostgreSQL, Oracle, etc.), the method you choose may vary. For MS Access, you can directly use the LAST() function, but for other systems like MySQL, PostgreSQL, and Oracle, the ORDER BY or MAX() methods are more common.