How to set primary key in phpmyadmin

The primary key of a table is one or more columns that uniquely identify each record in the table. Here are the steps to set a primary key: Log in to phpMyAdmin. Select database and table. Check the column you want to use as the primary key. Click "Save Changes". Primary keys provide data integrity, lookup speed, and relationship modeling benefits.

How to set the primary key of the MySQL database table

Steps to set the primary key:

1. Login to phpMyAdmin.
2. Select the database and table where you want to set the primary key.
3. Navigate to the Table Structure tab.
4. Check the column to be used as the primary key in the check box under "Primary Key".
5. Click the "Save Changes" button.

Detailed expansion:

1. Define the primary key

The primary key is one or more columns in the table , used to uniquely identify each record in the table. Primary key values ​​must be unique and cannot be NULL.

2. Set the primary key

You can set the primary key in the following two ways:

• Through phpMyAdmin:Follow Follow the steps listed above.
• By SQL statement: Use the following SQL statement:

<code>ALTER TABLE <table_name> ADD PRIMARY KEY (<column_name>);</column_name></table_name></code>

3. Select the primary key column

Select as When selecting primary key columns, the following factors should be considered:

• Uniqueness: The value of the column must be unique.
• Non-null: Column cannot contain NULL values.
• Performance: Columns frequently used in queries as primary keys can improve performance.

4. Multi-column primary key

You can specify multiple columns as primary keys in the same table, which is called a composite primary key. A composite primary key consists of multiple columns that are uniquely combined.

5. Advantages of primary key

Setting the primary key has the following advantages:

• Data integrity:The primary key ensures Records in the table are unique.
• Search speed: The primary key is used to quickly find specific records in the table.
• Relationship modeling: Through foreign keys, primary keys can be used to connect different tables.

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