I am using MySQL. I have a select statement followed by a number of insert statement done using the C Connector. I would like to know how to put them all under one transaction and finally commit then.
I have gone through the MySQL 5.0 Reference Manual and C API Function Overview it have this function mysql_commit()? I must have a start transaction (how to set this is it by just turning off the autocommit()) and finally only commit right?
As far as I understand, there is no mysql_starttransaction() or something similar; so you're stuck with something like:
mysql_autocommit(conn, 0);
//Do stuff here
mysql_commit(conn); //...or mysql_rollback(conn);
I would rather use the "query" method for all these calls:
mysql_query(conn, "START TRANSACTION");
//Do stuff here
mysql_query(conn, "COMMIT"); //...or mysql_query(conn, "ROLLBACK");
Also see this documentation.
Related
There are few example out there but non of them are very clarified (or on old version).
I want to call MySQL procedure and check the return status (in rails 4.2). The most common method I saw is to call result = ActiveRecord::Base.connection.execute("call example_proc()"), but in some places people wrote there is prepared method result = ActiveRecord::Base.connection.execute_procedure("Stored Procedure Name", arg1, arg2) (however it didn't compiled).
So what is the correct way to call and get the status for MySQL procedure?
Edit:
And how to send parameters safly, where the first parameter is integer, second string and third boolean?
Rails 4 ActiveRecord::Base doesn't support execute_procedure method, though result = ActiveRecord::Base.connection still works. ie
result = ActiveRecord::Base.connection.execute("call example_proc('#{arg1}','#{arg2}')")
You can try Vishnu approach below
or
You can also try
ActiveRecord::Base.connections.exec_query("call example_proc('#{arg1}','#{arg2}')")
here is the document
In general, you should be able to call stored procedures in a regular where or select method for a given model:
YourModel.where("YOUR_PROC(?, ?)", var1, var2)
As for your comment "Bottom line I want the most correct approach with procedure validation afterwards (for warnings and errors)", I guess it always depends on what you actually want to implement and how readable you want your code to be.
For example, if you want to return rows of YourModel attributes, then it probably would be better if you use the above statement with where method. On the other hand, if you write some sql adapter then you might want to go down to the ActiveRecord::Base.connection.execute level.
BTW, there is something about stored proc performance that should be mentioned here. In several databases, database does stored proc optimization on the first run of the stored proc. However, the parameters that you pass to that first run might not be those that will be running on it more frequently later on. As a result, your stored-proc might be auto-optimized in a "none-optimal" way for your case. It may or may not happen this way, but it is something that you should consider while using stored procs with dynamic params.
I believe you have tried many other solutions and got some or other errors mostly "out of sync" or "closed connection" errors. These errors occur every SECOND time you try to execute the queries. We need to workaround like the connection is new every time to overcome this. Here is my solution that didn't throw any errors.
#checkout a connection for Model
conn = ModelName.connection_pool.checkout
#use the new connection to execute the query
#records = conn.execute("call proc_name('params')")
#checkout the connection
ModelName.connection_pool.checkin(conn)
The other approaches failed for me, possibly because ActiveRecord connections are automatically handled to checkout and checking for each thread. When our method tries to checkout a connection just to execute the SP, it might conflict since there will be an active connection just when the method started.
So the idea is to manually #checkout a connection for the model instead of for thread/function from the pool and #checkin once the work is done. This worked great for me.
I am a beginner to lua language.The main concept is when a user fire the DROP TABLE command in mysql it should not be executed.But he can fire all other commands as usual in mysql.But i don't want to use GRANTS for this.Is there any luaScript to perform this action via mysql-proxy?
For example:
mysql> DROP TABLE T1;
Please wait for authentication
Also is LuaSql helpful to perform this task via mysql-proxy?
Hope i made the idea clear.Someone help me solve out this issue.Thanks in advance.
Yes, you can do that. The idea here is to check a query whether or not it fulfills the requirements you want to filter and if so NOT sending it to the server
function read_query(packet)
if string.byte(packet) == proxy.COM_QUERY then
query = packet:sub(2)
if condition(query) then
proxy.response = {
type = proxy.MYSQLD_PACKET_OK,
}
return proxy.PROXY_SEND_RESULT
end
end
end
This checks each query the proxy receives for condition and if it matches it will just return a SUCCESS to the client without delivering the query. Thus effectively dropping the query.
I was wondering if there is a function such as mysql rollback commit available in
Zend Framework 2?
I need to insert multiply rows in the same tabel coming from one form submit.
Nick
In ZF2, the beginTransaction(), commit() and rollback() methods are in the ConnectionInterface.
As far as I can see, you probably have to write code something like this:
$dbAdapter->getDriver()->getConnection()->beginTransaction();
. . .
$dbAdapter->getDriver()->getConnection()->commit();
See:
http://framework.zend.com/apidoc/2.1/classes/Zend.Db.Adapter.Driver.ConnectionInterface.html
This cannot be used to update two tables in the same transaction.
Using CI for the first time and i'm smashing my head with this seemingly simple issue. My query wont insert the record.
In an attempt to debug a possible problem, the insert code has been simplified but i'm still getting no joy.
Essentially, i'm using;
$data = array('post_post' => $this->input->post('ask_question'));
$this->db->insert('posts', $data);
I'm getting no errors (although that possibly due to disabling them in config/database.php due to another CI related trauma :-$ )
Ive used
echo print $this->db->last_query();
to get the generated query, shown as below:
INSERT INTO `posts` (`post_post`) VALUES ('some text')
I have pasted this query into phpMyAdmin, it inserts no problem. Ive even tried using $this->db->query() to run the outputted query above 'manually' but again, the record will not insert.
The scheme of the DB table 'posts' is simply two columns, post_id & post_post.
Please, any pointers on whats going on here would be greatly appreciated...thanks
OK..Solved, after much a messing with CI.
Got it to work by setting persistant connection to false.
$db['default']['pconnect'] = FALSE;
sigh
Things generally look ok, everything you have said suggests that it should work. My first instinct would be to check that what you're inserting is compatible with your SQL field.
Just a cool CI feature; I'd suggest you take a look at the CI Database Transaction class. Transactions allow you to wrap your query/queries inside a transaction, which can be rolled back on failure, and can also make error handling easier:
$this->db->trans_start();
$this->db->query('INSERT INTO posts ...etc ');
$this->db->trans_complete();
if ($this->db->trans_status() === FALSE)
{
// generate an error... or use the log_message() function to log your error
}
Alternatively, one thing you can do is put your Insert SQL statement into $this->db->query(your_query_here), instead of calling insert. There is a CI Query feature called Query Binding which will also auto-escape your passed data array.
Let me know how it goes, and hope this helps!
We have a lot of queries
select * from tbl_message
that get stuck on the state "Writing to net". The table has 98k rows.
The thing is... we aren't even executing any query like that from our application, so I guess the question is:
What might be generating the query?
...and why does it get stuck on the state "writing to net"
I feel stupid asking this question, but I'm 99,99% sure that our application is not executing a query like that to our database... we are however executing a couple of querys to that table using WHERE statement:
SELECT Count(*) as StrCount FROM tbl_message WHERE m_to=1960412 AND m_restid=948
SELECT Count(m_id) AS NrUnreadMail FROM tbl_message WHERE m_to=2019422 AND m_restid=440 AND m_read=1
SELECT * FROM tbl_message WHERE m_to=2036390 AND m_restid=994 ORDER BY m_id DESC
I have searched our application several times for select * from tbl_message but haven't found anything... But still our query-log on our mysql server is full of Select * from tbl_message queries
Since applications don't magically generate queries as they like, I think that it's rather likely that there's a misstake somewhere in your application that's causing this. Here's a few suggestions that you can use to track it down. I'm guessing that your using PHP, since your using MySQL, so I'll use that for my examples.
Try adding comments in front of all your queries in the application, like this:
$sqlSelect = "/* file.php, class::method() */";
$sqlSelect .= "SELECT * FROM foo ";
$sqlSelect .= "WHERE criteria";
The comment will show up in your query log. If you're using some kind database api wrapper, you could potentially add these messages automatically:
function query($sql)
{
$backtrace = debug_backtrace();
// The function that executed the query
$prev = $backtrace[1];
$newSql = sprintf("/* %s */ ", $prev["function"]);
$newSql .= $sql;
mysql_query($newSql) or handle_error();
}
In case you're not using a wrapper, but rather executing the queries directly, you could use the runkit extension and the function runkit_function_rename to rename mysql_query (or whatever you're using) and intercept the queries.
There are (at least) two data retrieval modes for mysql. With the c api you either call mysql_store_result() or mysql_use_result().
mysql_store_result() returns when all result data is transferred from the MySQL server to your process' memory, i.e. no data has to be transferred for further calls to mysql_fetch_row().
However, by using mysql_use_result() each record has to be fetched individually if and when mysql_fetch_row() is called. If your application does some computing that takes longer than the time period specified in net_write_timeout between two calls to mysql_fetch_row() the MySQL server considers your connection to be timed out.
Temporarily enable the query log by putting
log=
into your my.cnf file, restart mysql and watch the query log for those mystery queries (you don't have to give the log a name, it'll assume one from the host value).