How can we read value have just insert in transaction - mysql

I am working on TRANSACTION MySql and I have a problem:
BEGIN;
INSERT INTO a(name) VALUES("hello");
SELECT * FROM a WHERE name = "hello";
COMMIT/ROLLBACK;
So I can not find the value I have just added into table a. Please help me if there is any way to SELECT value that have just added.
Thanks a lot

If you want the auto increment ID value for the row you just inserted, you can get it with SELECT LAST_INSERT_ID().
If you want the whole row you just inserted, do this, assuming your table's autoincrement id is called id.
INSERT INTO a whatever;
SELECT * FROM a WHERE id = LAST_INSERT_ID();
You don't need an explicit transaction for this sequence of queries to work correctly. But, you can still use one for other purposes.

Related

get the last ID after insert in mysql

how can i get the ID of the last insert statement
im using trigger to create a ID for every record
INSERT INTO table1_seqdocument VALUES (NULL);
SET NEW.tracknum = CONCAT('DOC', LPAD(LAST_INSERT_ID(), 3, '0'));
and i need that ID for other table
this is this my insert statement
INSERT INTO tble_transaction
(
tracknum
,signatoryid
,signed
,status
,signatorylevel
)
VALUES
(?,?,?,?,? )
what i want is to retrieve the ID and use it for another insert statement but using other table. is it possible? thank you
You can use ##identity
SELECT ##IDENTITY AS [##IDENTITY];
LAST_INSERT_ID() can only tell you the ID of the most recently auto-generated ID for that entire database connection, not for each individual table, which is also why the query should only read SELECT LAST_INSERT_ID() - without specifying a table. As soon as you fire off another INSERT query on that connection, it gets overwritten. If you want the generated ID when you insert to some table, you must run SELECT LAST_INSERT_ID() immediately after doing that (or use some API function which does this for you).
If you want the newest ID currently in an arbitrary table, you have to do a SELECT MAX(id) on that table, where id is the name of your ID column. However, this is not necessarily the most recently generated ID, in case that row has been deleted, nor is it necessarily one generated from your connection, in case another connection manages to perform an INSERT between your own INSERT and your selection of the ID.
(For the record, your query actually returns N rows containing the most recently generated ID on that database connection, where N is the number of rows in table1.)

Accessing last inserted row in mysql

On my db-server i am inserting data in a table having a auto increment field say 'id'. Now i want to use the value of this last inserted 'id' in subsequent steps. I can use this:-
select * from table_name order by id desc limit 1;
But the problem here is, it is a server and many more insertions could be happening and there could be a case where i try to retrieve the data with the query i mentioned and get a different id ie. between my insert and select there could be some other insert and i wont get the value i inserted. Any way in which this could be addressed.?
Thanks in advance.
Use this
mysql_insert_id(&mysql);
as its basic structure are
mysql_insert_id ([ resource $link_identifier = NULL ] )
Retrieves the ID generated for an AUTO_INCREMENT column by the previous query (usually INSERT).
or in mysql use
SELECT LAST_INSERT_ID();
here is the ref links
http://dev.mysql.com/doc/refman/5.0/en/getting-unique-id.html
http://php.net/manual/en/function.mysql-insert-id.php
try this
SELECT LAST_INSERT_ID(colid) From tablename;
heres the Link
call LAST_INSERT_ID() function immediately after insertion and save id somewhere.
Use this mysql_insert_id()
It returns the AUTO_INCREMENT ID generated from the previous INSERT operation.
This function returns 0 if the previous operation does not generate an AUTO_INCREMENT ID, or FALSE on MySQL connection failure.
you can get the id if you call LAST_INSERT_ID() function immediately after insertion and then you can use it.
For any last inserted record will be get through mysql_insert_id()
If your table contain any AUTO_INCREMENT column it will return that Value.
mysql_query("INSERT INTO test(emsg,etime) values ('inserted',now())");
printf("Last inserted record has id %d\n", mysql_insert_id());
$last_id=mysql_insert_id();
echo $last_id;
?>

Is there a way to get last inserted id of a NON - auto incremented column in MySQL?

I know how LAST_INSERT_ID() works for auto incremented columns, but I cannot find a way to get the last id I inserted for a non auto incremented column.
Is there a way I can do that?
you can easily do that using the same LAST_INSERT_ID().
INSERT INTO thetable (id, value)
VALUES (LAST_INSERT_ID(126), 'some data');
SELECT LAST_INSERT_ID(); -- returns 126
I'm assuming you want the retrieve this last inserted id at some later point after inserting it, since if you need it right after inserting it you obviously would already know what the id is.
The only way you'll be able to get that is to have another column on the table that can indicate which row was last inserted, such as a timestamp or datetime column. If your ids are unique and increasing, you can just use that column. Then you just select 1 row ordered by that column in descending order.
For example
INSERT INTO my_table (id, timestamp) VALUES (123, NOW())
SELECT id FROM my_table ORDER BY timestamp DESC LIMIT 1
Edit: as per the comments below, you're much better off using an AUTO_INCREMENT column, though this column doesn't have to be the id column, you could add an auto-increment insert_order column of type Int and simply order by that.
I assume that you need the ID to find your just inserted row, rather to find the last inserted row. In a web application, you can never be sure that the last inserted row is the one you have just created.
You could use a GUID as id in this case. A GUID is usually stored as a string of length 36 or as a 16byte blob. The GUID can be created before inserting the row, and then can be stored while inserting the row.
Since the id is not auto incremented as you stated, you have to generate it anyway before inserting the row. The safest way to do this is to create a GUID which should be unique enough. Otherwise you would have to determine the last unused ID, what can be tricky and risky.
The easiest way I found to do this is to set a variable.
Unlike using LAST_INSERT_ID which only returns and INT this way you can use other unique identifiers.
SET #id = UUID();
INSERT INTO users (
id
)
VALUES (
#id
);
SELECT * FROM users WHERE id = #id;
No.
There is no inherent ordering of relations, no "last-inserted record". This is why the AUTO_INCREMENT field exists, after all.
You'd have to look in logs or cache the value yourself inside your application.
There's no way with mysql. But you can to do it programmatically. Without an auto-incrementing ID column there's no way for the database to know which records were inserted last.
One way to do is use such as a column containing timestamp or datetime values. and get id of latest value of tmestamp to get last inserted record
If you want to get a custom last_inserted ID, you must implement a procedure that will make the insert statment on your DB.
At the end, just print the ID and use the PHP (if PHP is your main script) sender to return the generated row.
EXAMPLE:
DROP PROCEDURE IF EXISTS insert_row;
DELIMITER $$
CREATE PROCEDURE insert_row(IN _row_id VARCHAR(255), IN _description VARCHAR(255))
BEGIN
SET #last_inserted_id = _row_id;
SET #sql = CONCAT("INSERT INTO test VALUES ('", _row_id, "','",_description,"')");
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SELECT #last_inserted_id AS LAST_INSERT_ID;
END;
$$
DELIMITER ;
#
#
#
#------- HOW TO USE IT ? ---------------
CALL insert_row('Test001','the first test line');
This worked for me in XAMPP
$qry = $con->query("INSERT INTO test_table(tbl_id, txt) VALUES(last_insert_id('15'), 'test value')");
print_r($con->insert_id);

Access Auto-Increment Value During INSERT INTO Statement

I am currently using MySQL. I have a table that has an auto_increment 'id' field, and an 'imgname' field containing a string that is the file name of an image.
I need to generate the 'imgname' value using the auto_increment value that is create by an INSERT INTO statement. The problem is, I don't know this value until I can use mysql_insert_id, AFTER the insert query has run. I would like to know if it's possible to access this value DURING the insert query somehow and then use it to generate my string in the query statement.
Thanks in advance.
I would keep the id and imgname independent of each other and combine the two on SELECT when needed. If the need is frequent enough, create a view.
Have a look at LAST_INSERT_ID() function. If performance is not an issue, INSERT regularly, and then UPDATE using LAST_INSERT_ID(), like:
UPDATE table SET name = CONCAT(name, "-", LAST_INSERT_ID()) WHERE id = LAST_INSERT_ID();

Edit the latest row in the database?

How can I edit the latest row in the database. I only know it's the last one. I don't know its id.
I don't know which language you are working with, in PHP's mySQL functions you can use
mysql_insert_id()
there are similar function in every other mySQL client library I know of.
Also, there is a native mySQL function!
LAST_INSERT_ID() (with no argument)
returns the first automatically
generated value that was set for an
AUTO_INCREMENT column by the most
recently executed INSERT statement to
affect such a column. For example,
after inserting a row that generates
an AUTO_INCREMENT value, you can get
the value like this:
mysql> SELECT LAST_INSERT_ID();
-> 195
Of course, a primary key with AUTO_INCREMENT is required for these functions to work.
For a table with an auto_increment id field:
UPDATE tbl SET col1 = 'val1' WHERE id = MAX(id);
If it's a row that has been inserted in your script (the same script from which you want to update it) and there is an auto_increment column on your table, you can get that auto_increment value, using functions such as those, for PHP :
mysql_insert_id
mysqli_insert_id
PDO::lastInsertId
There should be an equivalent for probably any language you can possibly be using for your application.
If your are trying to do an update from another script than the one in which you did the insert, and still have an auto_increment column, the best way will probably be to update the row that has the biggest value for that column :
update your_table
set your_column = ...
where id = max(id)
Or, in two steps (not sure it'll work in one) :
select max(id) as id from your_table
update your_table set your_column = ... where id = [what you got with thr first query]
You can also use UPDATE table SET ... WHERE id=LAST_INSERT_ID() (supposing the last insert was on the table you want to query).
I would not use TWO steps to find the last insert ID simply because a new record could be added in the mean time.
Depending on your version, you should be able to call $handle->last_id(); or $handle->{mysql_insertid};
Chris