Skip to main content

how to insert data into 2 tables by using one sql query?

Here's how you can structure your SQL queries to insert data into two tables, depending on whether they are related or not:

1. Inserting Data into Two Tables Without a Relationship

If the two tables do not have a relationship, you can simply execute two separate INSERT statements within a single transaction to ensure atomicity:

BEGIN TRANSACTION

-- Insert data into the first table
INSERT INTO FirstTable (Column1, Column2, ...)
VALUES (Value1, Value2, ...)

-- Insert data into the second table
INSERT INTO SecondTable (ColumnA, ColumnB, ...)
VALUES (ValueA, ValueB, ...)

COMMIT TRANSACTION

2. Inserting Data into Two Related Tables

If there is a relationship (e.g., foreign key) between the two tables, you typically need to insert data into the primary (parent) table first and then use the generated key (e.g., ID) to insert data into the related (child) table.

Using a Stored Procedure:

You can utilize a stored procedure to handle this more efficiently:

CREATE PROCEDURE InsertDataIntoRelatedTables
    @Column1 VARCHAR(50),
    @Column2 VARCHAR(50),
    @ColumnA VARCHAR(50),
    @ColumnB VARCHAR(50)
AS
BEGIN
    BEGIN TRANSACTION

    DECLARE @PrimaryKeyID INT

    -- Insert data into the primary (parent) table
    INSERT INTO PrimaryTable (Column1, Column2, ...)
    VALUES (@Column1, @Column2, ...)

    -- Retrieve the generated primary key
    SET @PrimaryKeyID = SCOPE_IDENTITY()

    -- Insert data into the related (child) table
    INSERT INTO RelatedTable (ForeignKeyColumn, ColumnA, ColumnB, ...)
    VALUES (@PrimaryKeyID, @ColumnA, @ColumnB, ...)

    COMMIT TRANSACTION
END

3. Example with Table Variables

Your example using table variables can be structured to reflect the relationship between objects, links, and data. Here’s how you can modify it:

DECLARE @Object_Table TABLE
(
    Id INT NOT NULL PRIMARY KEY
)

DECLARE @Link_Table TABLE
(
    ObjectId INT NOT NULL,
    DataId INT NOT NULL
)

DECLARE @Data_Table TABLE
(
    Id INT NOT NULL IDENTITY(1,1),
    Data VARCHAR(50) NOT NULL
)

-- Insert objects
INSERT INTO @Object_Table (Id) VALUES (1)
INSERT INTO @Object_Table (Id) VALUES (2)

-- Insert data
INSERT INTO @Data_Table (Data) VALUES ('Data One')
INSERT INTO @Data_Table (Data) VALUES ('Data Two')

-- Link all data to the first object
INSERT INTO @Link_Table (ObjectId, DataId)
SELECT Objects.Id, Data.Id
FROM @Object_Table AS Objects, @Data_Table AS Data
WHERE Objects.Id = 1

-- Insert new data and link it to the second object
INSERT INTO @Data_Table (Data)
OUTPUT 2, INSERTED.Id INTO @Link_Table (ObjectId, DataId)
VALUES ('Data Three')

Explanation:

  • Without a Relationship: Two separate INSERT statements are executed. A transaction is used to ensure both inserts succeed or fail together.
  • With a Relationship:
    • Data is first inserted into the parent table.
    • The SCOPE_IDENTITY() function retrieves the ID of the newly inserted row.
    • This ID is then used to insert related data into the child table.
  • Table Variables: In your example, table variables are used to simulate this scenario. Data is inserted into @Object_Table and @Data_Table, and then linked in @Link_Table.

This approach ensures that the data integrity is maintained while inserting related data across multiple tables.

Comments

Post a Comment

Popular posts from this blog

OOP Concept with Real Time Examples

A design philosophy is OOP. Object Oriented Programming is what it stands for. In contrast to outdated procedural programming languages, object-oriented programming (OOP) employs a separate set of programming languages. In OOP, everything is categorised as self-sustaining "objects". As a result, you achieve re-usability using the four core concepts of object-oriented programming. Programmes are organised around objects and data rather than action and logic in the object-oriented programming (OOP) paradigm.    Let's use your "Leg" as an example to grasp the object orientation clearly. The class "Leg" is one. Left and right legs are objects of type Leg on your body. A series of electrical impulses supplied through your body parts (through an interface) are what manage or control their primary functions. As a result, the body part serves as an interface between your body and your legs. The Leg is a well-designed class. The attributes of the Leg are m...
6 comments
Read more

Windows Application Development - Dotnet Environment Basic understandings

The development life cycle for creating Windows desktop applications using the .NET framework typically involves several stages. Here's an overview of the typical life cycle: Requirement Analysis: Gather and analyze the requirements for the Windows application. Understand the business needs, user expectations, features, and functionalities that the application should have. Design: Create a design for your application's user interface (UI) and overall architecture. Decide on the layout, controls, navigation flow, and other visual aspects. Plan the data storage mechanisms, database schema, and integration with other systems if necessary. Development: Begin coding the application using the .NET framework. Use programming languages like C# or VB.NET. Create classes, forms, controls, and implement the business logic. You'll work on creating the UI, handling user interactions, data processing, and any required integrations. Testing: Thoroughly test the applicatio...
Post a Comment
Read more

Web API - ASP DOTNET, MVC

We will attempt to grasp what a Web API is in this post, as well as the fundamental elements of a Web API project. HTTP is a potent foundation for creating REST-compliant APIs that expose services and data. Almost any platform can use the HTTP library. An excellent framework for developing RESTful applications is the ASP.Net Web API.A wide range of clients, including browsers, mobile devices, and desktop programmes, are served by the Net Framework. Although WCF may be used to create RESTful services as well, there are two key arguments in favour of Web API usage among users. The inclusion of ASP.NET Web API in ASP.NET MVC clearly increases the use of the TDD (Test Data Driven) approach in the creation of RESTful services. RESTful services can be easily developed utilizing web APIs whereas WCF still requires a lot of configuration settings, URI templates, contracts, and endpoints. MVC creating Web APIs is supported natively by ASP.Net core. Applications' ability to communicate wit...
Post a Comment
Read more