While executing different queries in PostgreSQL, it is very much possible that we can encounter some errors. We definitely need to fix these errors in order to get the expected output result from the query. An error i.e. “function ntile() Does Not Exist” shows up when we execute the function, ntile(). This function divides a segment into different groups also called buckets. The function tries to divide the rows equally. Let’s find out the reason why we encounter the error “function ntile() Does Not Exist” and its appropriate solution using examples.

How to Resolve Error “function ntile() Does Not Exist” in PostgreSQL?

While executing the queries using this ntile() function, we usually encounter the error “function ntile() Does Not Exist” as shown in the following output:

The error, “function ntile() Does Not Exist” occurs when we do not pass any argument in the ntile() function. The ntile() function takes in an integer that specifies the number of buckets/parts we want to divide our table rows into. Let’s see how can we fix this error with the help of an example:

Example: How to Fix “function ntile() Does Not Exist” Error in PostgreSQL?

Let’s consider that we wrote the query to partition the data of the table named “test_scores” into 4 buckets. The query looks like this:

SELECT *,
 ntile( ) 
 OVER ( ORDER BY candidate_id ) 
 AS "ntile"
 FROM test_scores;

Running this query results in an error that the “function ntile() Does Not Exist”. Now in the above query, we can see that the ntile() function has not been provided with any argument, which is the primary/main reason for this error.

Now let’s pass “4” as an argument in the function which will instruct the function to make 4 buckets from the total rows of the table. The query will be as follows:

SELECT *,
  ntile(4) 
  OVER (ORDER BY candidate_id ) 
  AS "ntile"
 FROM test_scores;

Executing this function will result in the expected output i.e. the function works fine and the error is removed.

The output for this query is:

We can see that the ntile() function has divided the whole table data rows into 4 almost equal buckets. This is the basic functioning of the ntile() function.

The argument must be an integer or numeric data and also the integer needs to be greater than 0. We can also encounter other errors due to the issue with the argument like if we give the argument as 0.

SELECT *,
  ntile(0) 
  OVER (ORDER BY candidate_id ) 
  AS "ntile"
 FROM test_scores;

The output will be:

Specifying the argument as 1 will give the whole table as it considers all the data as one bucket.

This is how we can resolve the “function ntile() Does Not Exist” error.

Conclusion

The error “function ntile() Does Not Exist” basically arises when we do not provide any argument to the ntile() function. The function requires a mandatory argument that has to be numeric type and should be greater than 0. Passing 1 as an argument will return the whole table as one bucket. In this post, we have learned how to resolve the “function ntile() Does Not Exist” error with practical examples.