DB2 CRUD Operations (Insert, Query, Update, Delete Data)

CRUD operations are a common data management model used to manipulate and manage data. Below is a detailed introduction to each step of CRUD operations:

Insert (Insertion)

An insert operation refers to adding new data into the database. This process typically involves creating or updating a new data record.

Steps for inserting into a table

1. Determine the data that needs to be inserted.

2. Select the table used to store this data.

3. Provide the required data in the table.

4. Execute the insert operation to add the data to the database.

Example

--Insert a record
INSERT INTO customers (name, email) VALUES ('John Doe', 'john.doe@example.com');

Query (Querying)

A query operation refers to retrieving specific data from the database. This process typically involves reading, displaying, or analyzing data from the database.

Steps for querying a table

1. Determine the data that needs to be queried.

2. Select the table used to store the required data.

3. Filter and sort based on conditions (e.g., WHERE clause) to retrieve specific data.

4. Execute the query operation to read the data out of the database.

Example

--Query all records
SELECT * FROM customers;

Update (Updating)

An update operation refers to changing or modifying existing data records. This process typically involves replacing, adding, or deleting data within a table.

Steps for updating a table

1. Determine the data that needs to be updated.

2. Select the table used to store the required data.

3. Provide the necessary changes.

4. Execute the update operation to modify the data in the database.

Example

--Update a record
UPDATE customers SET email = 'johndoe@example.com' WHERE name = 'John Doe';

Delete (Deletion)

A delete operation refers to removing or deleting specific data from the database. This process typically involves deleting or hiding data within a table.

Steps for deleting from a table

1. Determine the data that needs to be deleted.

2. Select the table used to store the required data.

3. Filter based on conditions (e.g., WHERE clause) to retrieve the data that needs to be deleted.

4. Execute the delete operation to remove the data from the database.

Example

--Delete a record
DELETE FROM customers WHERE name = 'John Doe';

In summary, CRUD operations are essential for effectively managing and manipulating data; understanding the details of each step can help you use your database more efficiently.