Cómo Insertar Datos y Manejar Errores en MySQL

What is an insert in MySQL and how is it used?

In any database related project, it is important to clearly understand the structure and logic behind the storage of information. Once the tables and their component fields have been clearly defined, the next crucial step is to add data using the insert command. This command allows you to specify in which table the data will be stored and exactly what information we are going to enter in each column or field.

The basic syntax for inserting data into a table is:

INSERT INTO table_name (field1, field2)VALUES  ('value1', 'value2');

From the previously defined structure, if certain fields have automatic values or allow null, then it is not necessary to explicitly insert them. This greatly facilitates this process.

How to ensure unique data in MySQL?

Maintaining unique values in a database is fundamental to safeguard its integrity. To do this, MySQL allows you to mark certain fields as unique, thus avoiding the entry of duplicates.

For example, when trying to insert a row with an existing value in a field marked as unique, MySQL will return an error indicating a duplicate entry. This immediately alerts the developer that something is wrong and requires revision.

Depending on the context we want to handle these errors, we can:

• Catch and process the error directly.
• Use INSERT IGNORE to ignore the failed insertion.
• Use a specific statement called ON DUPLICATE KEY UPDATE.

What is the difference between insert ignore and on duplicate key update?

Understanding the practical difference between these two options is vital to optimize our workflow when inserting data:

Insert ignore:

• This will not throw visible errors when attempting to insert duplicate data.
• It simply causes the operation to fail silently displaying only warnings.

Example:

INSERT IGNORE INTO products(name,  slog)VALUES  ('Blue-feather','blue-feather');

On duplicate key update: This option gives much more control over what happens in case you try to insert a duplicate data.

Practical example:

INSERT INTO products (name,  slog)VALUES  ('Blue feather', 'blue-feather')ON DUPLICATE  KEY UPDATE  description='Item updated in duplicate';

This will automatically update the existing row instead of failing or ignoring.

What does the concat combination and math functions allow in MySQL?

When managing databases, it is common to need to generate descriptions or perform numeric operations dynamically. The concat() functions and common mathematical operations, integrated into SQL statements, allow you to fulfill these purposes efficiently.

• Concat: Combines several text fragments or numbers into a single string.

Example:

SELECT CONCAT('Hello ', name) FROM products;

• Numeric functions: You can do direct mathematical operations using stored values.

Practical example to multiply a price by a number of products:

UPDATE products SET total_price  = price  * quantity;

These combinations are especially useful when relating and managing data that require frequent and varied calculations.

How to insert multiple records in a single statement?

MySQL allows you to insert multiple records simultaneously using a concise and practical structure. You only need to separate multiple data tuples with commas within the same insert statement.

Example:

INSERT INTO products (name,  slog, description)VALUES ('Black feather', 'black-feather', 'Description here'),('Pink-feather', 'pink-feather', 'Other description here');

In this way, the insertion process becomes extremely efficient when handling large volumes of data.

Would you like to comment on your experience?

What has been your biggest challenge when working with inserts and handling duplicate data in databases? Leave a comment and share your experience with us.