Embedded SQL in DBMS

Embedded SQL in DBMS is one of the finest and best approaches for integrating the application code with the SQL statements directly. This approach bridges the gap between the SQL statement, DB connection and the application code. It allows the developers to write seamless SQL statements within the application code. Also, read: Advanced SQL in DBMS

Let’s look in detail at how Embedded SQL in DBMS works.

What is Embedded SQL in DBMS?

Embedded SQL in DBMS is a technique which allows SQL statements to be directly included within the programming languages such as C, C++, Java, Python, etc. Basically, the general-purpose programming logic is combined with database operations in a single application.

Database management System or DBMS provides some API calls or special syntax that allows developers to embed the SQL statements directly in their source programming code. At last, these SQL embed Statements are processed by the DBMS at runtime.

How does the Embedded SQL in DBMS work?

• Connection to the database: Connection to the database to be established first, it can be done either by using any specific function provided by the programming language or any specific Database Management library.
• Preparation of SQL Statement: Preparation of SQL Statement generally involves writing the SQL statement directly in the code using the specific format given by the Database management system.
• Binding Variables: Binding variables is mainly used if there are some variables whose values need to be changed dynamically in the SQL statement that can be bound using placeholders. These placeholders are later replaced with the actual values, at the time of the execution of the statement.
• Execution of the statement: Now, the time is to execute the SQL statement. This should be done with the proper functions provided by the DBMS. The statement is parsed by the DBMS, and then DBMS optimize the statement, and performs the operations that are being requested, it can be either retrieval, deletion, insertion or updation on the database.
• Handling Result: This is based on the output given after the execution of the statement. It basically involves iterating towards the result sets, extraction of data, and fetching rows.
• Termination of Connection: Once all the above steps are finished and the database operations are ready to release the resources, the database connection should be closed.

Why do we need Embedded SQL in DBMS?

Embedded SQL in DBMS has several benefits and thus has many reasons for its usage.

• Seamless Integration: Embedded SQL in DBMS allows us seamlessly to integrate all our database operations within the application code. It doesn’t need switching between the interface and environments for integration. The SQL statements can be directly added to the program or application code. So basically no need for separate modules for incorporating these statements. The development is being simplified and performance is being improved.
• Enhancement of Performance: Embedded SQL in DBMS, helps in performance improvement and enhancements.
  As, in this, the DBMS can optimize and analyze the SQL statements along with the logical program from the surroundings and can result in the best execution of the results.
• Managing Transaction: Embedded SQL in DBMS allows to manage the transactions of the databases within the application code itself. Transactions can be initiated, committed, rollback, and can perform all the necessary transactions and all these should be defined within the boundaries of the transactions in the application code itself. This helps in maintaining the consistency of the data, and data integrity.
• Manipulation of Data and Business Logic: With the help of Embedded SQL in DBMS, business logic and manipulation of the data can be combined into a single application. It helps in constructing complex algorithms, handling inputs from the users, and performing lots of transformations with data.
• Parameterized Queries: In Embedded SQL in DBMS, the parameters like variables can be bound within the SQL statements. This is a very important feature as it prevents SQL injection attacks by separating the SQL statements from the user’s inputs. without compromising the security, it allows dynamic values to be passed in the SQL statement.
• Code can be Reusable: Embedded SQL in DBMS allows code reusability. As, when the SQL code in being embedded in the application, then the same code can be used in multiple parts of the application. This basically helps in promoting the modular design of the application and reduces the duplication of the code. If there are some changes needed, it needs to be done in one place and that will get reflected in all the places and thus helps in improving maintainability.
• Debugging and Handling Errors: Embedded SQL in DBMS also maintains error handling. Embedded SQL helps in handling and reporting database-related errors. Exceptions can be matched, error codes available to be checked, and handing error conditions within the application code. Through this, error-handling strategies can be improved and better error-handling mechanisms can be followed within the application code.

Read about DBMS Basic Introduction to SQL

What is the structure of Embedded SQL in DBMS?

Embedded SQL in DBMS follows the specific structure and set of rules that are used for combining the SQL statements within the application code. Let’s have a look at the general structure and the flows that generally remain constants.

• Necessary Headers or Libraries to be Included: It starts by including the necessary header files that import all the important functions that are being used for defining the Embedded SQL in DBMS within the application code and the chosen programming language. These headers are generally provided by the DBMS itself.
• Connection of the Database: In Embedded SQL in DBMS, the connection to the database should be established using the functions provided by the DBMS library that was imported in the 1st step. This step is very important as it helps in interacting with the database.
• Preparation of the SQL statements: Now the SQL statement should be written directly within the application code as per the programming language chosen. These SQL statements can be either SELECT, INSERT, UPDATE, DELETE, and other SQL operations.
• Bind Variables: This is for any dynamic values or the parameters needed by the SQL Statements. These variables will be replaced by the original or the actual values when the SQL statements are executed.
• Execution of the SQL Statement: Now the statements that are being embedded should be executed. By using the appropriate functions the statements should be expected. The DBMS will first process the statements, optimize them, and then perform all the requested actions on the database.

Sample Code demonstrating the Embedded SQL in DBMS

Below is the sample code demonstrating how the SQL statements can be embedded within the Application code. The programming language chosen here is C++.

#include <dbms_library.h>
#include <iostream.h>
using namespace std;
int main() {

// Database connection to be established
db_connect();

// SQL statement to be prepared and executed
db_prepare("INSERT INTO users (name, phone) VALUES (?, ?)");
db_bind_param("Rocky Joe, "1234567891");
db_execute();

// Results are handled
db_fetch_results();

// Handling Errors if any
if (db_error()) {
handle_error(db_error_message());
}

// Database connection to be closed once it is executed
db_disconnect();
return 0;

}

Therefore, Embedded SQL in DBMS is one of the best and most powerful techniques that help in combining the SQL Statements within the Application Code. It bridges the gap between the database operations and the programming application logic within the Database Management System (DBMS). This integration offers one of the most efficient and seamless approaches to developing applications that rely on the interaction of the database.