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26 Απρ 2011 · This happens when MySQL can not determine a proper auto_increment value. In your case, MySQL choose 1 as next auto_increment value, however there is already row with that value in the table. One way to resolve the issue is to choose a proper auto_increment value yourself: ALTER TABLE ...
What is an AUTO INCREMENT Field? Auto-increment allows a unique number to be generated automatically when a new record is inserted into a table. Often this is the primary key field that we would like to be created automatically every time a new record is inserted.
With innodb_autoinc_lock_mode set to 2 (“interleaved”), there may be gaps in the auto-increment values generated by “bulk inserts,” but only if there are concurrently executing “INSERT-like” statements.
19 Ιουλ 2024 · In MySQL, the AUTO_INCREMENT attribute is used to generate a unique identifier for new rows in a table. This attribute is often applied to primary key columns to ensure that each row can be uniquely identified. This article will explore the AUTO_INCREMENT attribute, how to use it, and various considerations to keep in mind.
You can retrieve the most recent automatically generated AUTO_INCREMENT value with the LAST_INSERT_ID() SQL function or the mysql_insert_id() C API function. These functions are connection-specific, so their return values are not affected by another connection which is also performing inserts.
In MySQL, you use the AUTO_INCREMENT attribute to automatically generate unique integer values for a column whenever you insert a new row into the table. Typically, you use the AUTO_INCREMENT attribute for the primary key column to ensure each row has a unique identifier.
You can use the following query to make document_id to increment automatically. ALTER TABLE document MODIFY COLUMN document_id INT auto_increment It is preferred to make document_id primary key as well. ALTER TABLE document MODIFY COLUMN document_id INT auto_increment PRIMARY KEY;
