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Learn how to create, name, and drop a PRIMARY KEY constraint in MySQL. A PRIMARY KEY uniquely identifies each record in a table and can consist of single or multiple columns.
In MySQL, a primary key is a column or a set of columns that uniquely identifies each row in the table. A primary key column must contain unique values. If the primary key consists of multiple columns, the combination of values in these columns must be unique.
Learn how to use PRIMARY KEY and UNIQUE constraints to enforce data integrity in MySQL tables. Find out how to handle errors, ignore violations, and use foreign keys with InnoDB and NDB storage engines.
Learn how to create and use the primary key constraint in MySQL tables. The primary key is a column or a combination of columns that uniquely identifies each row in a table.
MySQL supports an IGNORE keyword for INSERT, UPDATE, and so forth. If you use it, MySQL ignores primary-key or unique-key violations and continues processing with the next row.
This MySQL tutorial explains how to create and drop a primary key in MySQL with syntax and examples. In MySQL, a primary key is a single field or combination of fields that uniquely defines a record.
Learn what primary keys are, the rules of primary keys, and how to use primary keys in MySQL. See examples of creating, adding, dropping, and generating primary keys in MySQL.
