Let's say I am doing a MySQL INSERT
into one of my tables and the table has the column item_id
which is set to autoincrement
and primary key
.
How do I get the query to output the value of the newly generated primary key item_id
in the same query?
Currently I am running a second query to retrieve the id but this hardly seems like good practice considering this might produce the wrong result...
If this is not possible then what is the best practice to ensure I retrieve the correct id?
This question is related to
mysql
insert
key
auto-increment
simply use "$last_id = mysqli_insert_id($conn);"
i used return $this->db->insert_id();
for Codeigniter
If you are using PHP: On a PDO object you can simple invoke the lastInsertId method after your insert.
Otherwise with a LAST_INSERT_ID you can get the value like this: SELECT LAST_INSERT_ID();
Here what you are looking for !!!
select LAST_INSERT_ID()
This is the best alternative of SCOPE_IDENTITY()
function being used in SQL Server
.
You also need to keep in mind that this will only work if Last_INSERT_ID()
is fired following by your Insert
query.
That is the query returns the id inserted in the schema. You can not get specific table's last inserted id.
For more details please go through the link The equivalent of SQLServer function SCOPE_IDENTITY() in mySQL?
You need to use the LAST_INSERT_ID() function with transaction:
START TRANSACTION;
INSERT INTO dog (name, created_by, updated_by) VALUES ('name', 'migration', 'migration');
SELECT LAST_INSERT_ID();
COMMIT;
http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_last-insert-id
This function will be return last inserted primary key in table.
From the LAST_INSERT_ID()
documentation:
The ID that was generated is maintained in the server on a per-connection basis
That is if you have two separate requests to the script simultaneously they won't affect each others' LAST_INSERT_ID()
(unless you're using a persistent connection perhaps).
If in python using pymysql, from the cursor you can use cursor.lastrowid
I just want to share my approach to this in PHP, some of you may found it not an efficient way but this is a 100 better than other available options.
generate a random key and insert it into the table creating a new row. then you can use that key to retrieve the primary key. use the update to add data and do other stuff.
doing this way helps to secure a row and have the correct primary key.
I really don't recommend this unless you don't have any other options.
If you need the value before insert a row:
CREATE FUNCTION `getAutoincrementalNextVal`(`TableName` VARCHAR(50))
RETURNS BIGINT
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
DECLARE Value BIGINT;
SELECT
AUTO_INCREMENT INTO Value
FROM
information_schema.tables
WHERE
table_name = TableName AND
table_schema = DATABASE();
RETURN Value;
END
You can use this in a insert:
INSERT INTO
document (Code, Title, Body)
VALUES (
sha1( concat (convert ( now() , char), ' ', getAutoincrementalNextval ('document') ) ),
'Title',
'Body'
);
BEWARE !! of LAST_INSERT_ID()
if trying to return this primary key value within PHP.
I know this thread is not tagged PHP, but for anybody who came across this answer looking to return a MySQL insert id from a PHP scripted insert using standard mysql_query
calls - it wont work and is not obvious without capturing SQL errors.
The newer mysqli
supports multiple queries - which LAST_INSERT_ID()
actually is a second query from the original.
IMO a separate SELECT
to identify the last primary key is safer than the optional mysql_insert_id()
function returning the AUTO_INCREMENT ID
generated from the previous INSERT
operation.
You will receive these parameters on your query result:
"fieldCount": 0,
"affectedRows": 1,
"insertId": 66,
"serverStatus": 2,
"warningCount": 1,
"message": "",
"protocol41": true,
"changedRows": 0
The insertId
is exactly what you need.
(NodeJS-mySql)
Source: Stackoverflow.com