The core method for getting the last inserted ID in MySQL is to use the LAST_INSERT_ID() function, which returns the autoincrement ID generated by the last insertion in the current connection. 1. Get the ID directly after insertion: Call LAST_INSERT_ID() immediately after executing the INSERT statement, which is suitable for tables with self-increment primary keys; 2. Use in programming languages: For example, PDO extension of PHP calls the function through lastInsertId() and Python's mysql-connector encapsulated; 3. Performance when inserting multiple lines: Return the ID of the first insert record, not the last; 4. Notes include: connection isolation ensures that it is not affected by other connections, it is also applicable in transactions, does not support non-self-increment fields, and pay attention to the call order in stored procedures. Mastering these key points can safely and effectively obtain the last inserted ID.
The most common method to get the last inserted ID in MySQL is to use LAST_INSERT_ID() function. This function returns the autoincrement ID generated by the last INSERT operation in the current connection, and it is at the connection level and will not be affected by other connection operations.
Below are some specific scenarios and usage methods that you may use.
Basic usage: Get the ID directly after inserting
This is the most common usage. After you have executed an INSERT statement, immediately call LAST_INSERT_ID() to get the autoincrement primary key value of the record just inserted.
INSERT INTO users (name, email) VALUES ('Tom', 'tom@example.com'); SELECT LAST_INSERT_ID();
- This method is only applicable to tables with autoincrement primary keys (
AUTO_INCREMENT). - Regardless of whether you explicitly pass in the primary key value, as long as this insert triggers the generation of the self-increment field,
LAST_INSERT_ID()can get the correct value.
Used in programming languages: Take PHP and Python as examples
Most database drivers or ORMs encapsulate calls to LAST_INSERT_ID() , but understanding the underlying mechanism is still important.
PHP (PDO)
$pdo->exec("INSERT INTO users (name, email) VALUES ('Jerry', 'jerry@example.com')");
$lastId = $pdo->lastInsertId();Python (using mysql-connector)
cursor.execute("INSERT INTO users (name, email) VALUES (%s, %s)", ("Lucy", "lucy@example.com"))
print(cursor.lastrowid) Behind these encapsulations are actually calling MySQL's LAST_INSERT_ID() function.
Performance when inserting multiple lines
If you insert multiple pieces of data at once, LAST_INSERT_ID() returns the ID of the first inserted record.
INSERT INTO users (name, email) VALUES ('A', 'a@example.com'), ('B', 'b@example.com'), ('C', 'c@example.com'); SELECT LAST_INSERT_ID(); -- Returns the ID of the first record
For example, if the start ID is 100, then the three records are 100, 101, and 102, respectively, and LAST_INSERT_ID() returns 100.
This needs to be paid attention to in some batch import logic.
Notes and FAQs
- Connection isolation : Each connection has its own independent
LAST_INSERT_ID(), so you don't have to worry about being affected by insertion by other users. - It is also applicable in transactions : you can get the ID normally even if you perform insertions in a transaction.
- Non-self-increment fields are not supported : if the generated ID is not inserted through the self-increment field, such as a UUID or manually specifying the primary key, then this function will not be used.
- Don't use it randomly in stored procedures : Pay attention to the order when calling it in stored procedures, otherwise you may not get the correct value.
Basically that's it. By mastering the usage scenarios and limitations of LAST_INSERT_ID() , you can safely obtain the ID of the newly inserted record during development.
The above is the detailed content of how to get last inserted id in mysql. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
What is GTID (Global Transaction Identifier) and what are its advantages?
Jun 19, 2025 am 01:03 AM
GTID (Global Transaction Identifier) ??solves the complexity of replication and failover in MySQL databases by assigning a unique identity to each transaction. 1. It simplifies replication management, automatically handles log files and locations, allowing slave servers to request transactions based on the last executed GTID. 2. Ensure consistency across servers, ensure that each transaction is applied only once on each server, and avoid data inconsistency. 3. Improve troubleshooting efficiency. GTID includes server UUID and serial number, which is convenient for tracking transaction flow and accurately locate problems. These three core advantages make MySQL replication more robust and easy to manage, significantly improving system reliability and data integrity.
What is a typical process for MySQL master failover?
Jun 19, 2025 am 01:06 AM
MySQL main library failover mainly includes four steps. 1. Fault detection: Regularly check the main library process, connection status and simple query to determine whether it is downtime, set up a retry mechanism to avoid misjudgment, and can use tools such as MHA, Orchestrator or Keepalived to assist in detection; 2. Select the new main library: select the most suitable slave library to replace it according to the data synchronization progress (Seconds_Behind_Master), binlog data integrity, network delay and load conditions, and perform data compensation or manual intervention if necessary; 3. Switch topology: Point other slave libraries to the new master library, execute RESETMASTER or enable GTID, update the VIP, DNS or proxy configuration to
How to connect to a MySQL database using the command line?
Jun 19, 2025 am 01:05 AM
The steps to connect to the MySQL database are as follows: 1. Use the basic command format mysql-u username-p-h host address to connect, enter the username and password to log in; 2. If you need to directly enter the specified database, you can add the database name after the command, such as mysql-uroot-pmyproject; 3. If the port is not the default 3306, you need to add the -P parameter to specify the port number, such as mysql-uroot-p-h192.168.1.100-P3307; In addition, if you encounter a password error, you can re-enter it. If the connection fails, check the network, firewall or permission settings. If the client is missing, you can install mysql-client on Linux through the package manager. Master these commands
Why do indexes improve MySQL query speed?
Jun 19, 2025 am 01:05 AM
IndexesinMySQLimprovequeryspeedbyenablingfasterdataretrieval.1.Theyreducedatascanned,allowingMySQLtoquicklylocaterelevantrowsinWHEREorORDERBYclauses,especiallyimportantforlargeorfrequentlyqueriedtables.2.Theyspeedupjoinsandsorting,makingJOINoperation
Why is InnoDB the recommended storage engine now?
Jun 17, 2025 am 09:18 AM
InnoDB is MySQL's default storage engine because it outperforms other engines such as MyISAM in terms of reliability, concurrency performance and crash recovery. 1. It supports transaction processing, follows ACID principles, ensures data integrity, and is suitable for key data scenarios such as financial records or user accounts; 2. It adopts row-level locks instead of table-level locks to improve performance and throughput in high concurrent write environments; 3. It has a crash recovery mechanism and automatic repair function, and supports foreign key constraints to ensure data consistency and reference integrity, and prevent isolated records and data inconsistencies.
What are the transaction isolation levels in MySQL, and which is the default?
Jun 23, 2025 pm 03:05 PM
MySQL's default transaction isolation level is RepeatableRead, which prevents dirty reads and non-repeatable reads through MVCC and gap locks, and avoids phantom reading in most cases; other major levels include read uncommitted (ReadUncommitted), allowing dirty reads but the fastest performance, 1. Read Committed (ReadCommitted) ensures that the submitted data is read but may encounter non-repeatable reads and phantom readings, 2. RepeatableRead default level ensures that multiple reads within the transaction are consistent, 3. Serialization (Serializable) the highest level, prevents other transactions from modifying data through locks, ensuring data integrity but sacrificing performance;
What are the ACID properties of a MySQL transaction?
Jun 20, 2025 am 01:06 AM
MySQL transactions follow ACID characteristics to ensure the reliability and consistency of database transactions. First, atomicity ensures that transactions are executed as an indivisible whole, either all succeed or all fail to roll back. For example, withdrawals and deposits must be completed or not occur at the same time in the transfer operation; second, consistency ensures that transactions transition the database from one valid state to another, and maintains the correct data logic through mechanisms such as constraints and triggers; third, isolation controls the visibility of multiple transactions when concurrent execution, prevents dirty reading, non-repeatable reading and fantasy reading. MySQL supports ReadUncommitted and ReadCommi.
How to add the MySQL bin directory to the system PATH
Jul 01, 2025 am 01:39 AM
To add MySQL's bin directory to the system PATH, it needs to be configured according to the different operating systems. 1. Windows system: Find the bin folder in the MySQL installation directory (the default path is usually C:\ProgramFiles\MySQL\MySQLServerX.X\bin), right-click "This Computer" → "Properties" → "Advanced System Settings" → "Environment Variables", select Path in "System Variables" and edit it, add the MySQLbin path, save it and restart the command prompt and enter mysql--version verification; 2.macOS and Linux systems: Bash users edit ~/.bashrc or ~/.bash_
