SQLite Stored Procedures

Introduction to SQLite Stored Procedures

SQLite does not provide the stored procedure concept; basically, stored procedure means we can prepare a single code, and that code we can reuse again and again as per user requirement. When we create the stored procedure, that means once we create the stored procedure that procedure, we can just call in your SQL statement to execute it. But we can use stored procedures in SQLite in a different way, that is, by creating a temporary single-row table. A stored procedure reduces the size of the SQL statement, giving fast access to access the data. For the stored procedure, we required the different parameters and that parameter we can use as per the user requirement.

Syntax:

create procedure specified procedure name ([specified statement]) as B;

Explanation:

• In the above syntax, we use a create procedure statement with different parameters.
• Here, the specified procedure name means the actual procedure name that we need to create; the specified statement means code for a procedure that we need to implement.

How to Create Stored Procedures in SQLite?

Now let’s see how to create stored procedures in SQLite:

• A procedure’s boundaries can be decorated with a kind determination; however, this sort of detail is disregarded; all boundaries acknowledge estimations of any sort, paying little mind to their announced sort. The boundary rundown can be unfilled. Boundaries are called by esteem; for example, the real qualities are duplicated when the method is called, and tasks to the boundaries in the body of the technique don’t influence any factors in the calling schedule.
• Put away systems don’t have their own exchange. They execute in the guest’s exchange setting; any alterations made by a put-away procedure are submitted or moved back alongside any changes made by the guest. Put away techniques might be finished by a RETURN articulation, yet this isn’t required. On the off chance that preparing arrives at the furthest square’s finish, a certain ‘RETURN NULL;’ articulation is executed. SQLite is heavenly.
• The way that it doesn’t have SQL syntax structure for stored procedure and functions is typically not impairment since it has an interface for the devouring application to enroll functions, which implies you will compose your functions in your favoured programming language. Win in general. Be that as it may, you do wish you could do it in SQL in some cases.
• The absence of Stored Procedures is normally alright—you can simply utilize contents. You may wish you had factors, yet you can make a one-line transitory table for those. Working around the absence of functions is more enthusiastically, yet here’s an illustration of how you can do it in extremis.

Examples of SQLite Stored Procedures

Given below are the different examples of creating procedures in SQLite as follows:

Example #1

Code:

CREATE PROCEDURE sample(a integer) AS
BEGIN
WHILE a>=1 LOOP
INSERT INTO demo_table VALUES (a);
a := a - 2;
END LOOP;
RETURN 'Inserted';
END;

Explanation:

• In the above example, we use the create procedure statement to create a new procedure name as a sample. Here we declared the variable as an integer; after that, we write some logical statement to insert new records into the demo_table shown in the above example.
• Here we specify the condition to insert the records into the demo_table; after that, we end the loop and returns inserted.
• End result of the above statement, as shown in the below screenshot as follows.

Output:

Example #2

Now let’s see another example of creating a procedure as follows.

Code:

create table sample as Select 4.4 as Base, 2 as Exponent;

Explanation:

• In the above example, we use the create table statement to create a new table name as a sample, and we define the value 4.4 for calculation with base value and exponent as shown in the above example.
• End result of the above statement, as shown in the below screenshot as follows.

Code:

.table

Output:

Now create a view by using the following statement as follows.

Code:

Drop View If Exists demo;
Create View demo As
WITH RECURSIVE de(exponent, exponent_remainder, base, result) as (
--FIRST EXPRESSION
SELECT exponent, exponent-1 , base, base
FROM sample
union all
--SECOND EXPRESSION
select sample.exponent, de.exponent_remainder -1, de.base, de.result * de.base
from sample
join de on sample.exponent = de.exponent
where de.exponent_remainder >= 1
)
select de.result
from de
where de.exponent_remainder = 1;

Explanation:

• In the above example, we define the procedure that we need; here, we first use the drop command to delete the exited view; after that, we use the create view command to create a new view name as a demo, as shown in the above example.
• Here we also define the recursive function with the de object of demo view. In the remaining part of the example, we fetch the sample table’s values with some mathematical calculation as shown. See, in this, we use to join constraint to join the sample table and demo view to get the desired result.
• End result of the above statement, as shown in the below screenshot as follows.

Output:

Now we can call the function by using the following statement as follows.

Code:

update sample set Base = 3.5, Exponent = 7; select Result from demo;

Explanation:

• In the above example, we use an update statement, and we set some new values such as Base = 3.5 and Exponent = 7, as shown in the above statement.
• End result of the above statement, as shown in the below screenshot as follows.

Output:

The components of the workaround are as follows:

• A single-row table for function with argument.
• Views that can be allude to the contentions table and do the count. Since you can utilize CTEs to do recursion, you could be programming anything thusly on a basic level.
• Similarly, we can create a different view as per the user requirement or, say, as per system requirement.

Conclusion

From the above article, we saw the basic syntax of a stored procedure, and we also see the different examples of stored procedure. We also saw the rules of stored procedure. From this article, we saw how and when we use the SQLite stored procedure.

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