Duplicate a record in MySQL
I have a table and I want to duplicate specific rows in the table. I know this is not the best way to do things but we are looking for a quick solution.
Here's something harder than I initially thought, all I need to do is copy an entire record to a new record in an 开发者_运维知识库auto-increment table in MySql without the need to specify each field. This is because the table can change in future and might break duplication. I will be duplicating MySQL records from PHP.
It is a problem because in a 'SELECT * ' query MySql will try to copy the ID of the record being copied which genenerates a duplicate ID error.
This blocks out:
INSERT INTO customer SELECT * FROM customer WHERE customerid=9181
. It also blocks out INSERT INTO customer (Field1, Field2, ...) SELECT Field1, Field2, ..... FROM customer WHERE customerid=9181.
Is there a way to do this from PHP or MySQL?
I finally found this code. I am sure it will help people in the future. So here it is.
function DuplicateMySQLRecord ($table, $id_field, $id) {
// load the original record into an array
$result = mysql_query("SELECT * FROM {$table} WHERE {$id_field}={$id}");
$original_record = mysql_fetch_assoc($result);
// insert the new record and get the new auto_increment id
mysql_query("INSERT INTO {$table} (`{$id_field}`) VALUES (NULL)");
$newid = mysql_insert_id();
// generate the query to update the new record with the previous values
$query = "UPDATE {$table} SET ";
foreach ($original_record as $key => $value) {
if ($key != $id_field) {
$query .= '`'.$key.'` = "'.str_replace('"','\"',$value).'", ';
}
}
$query = substr($query,0,strlen($query)-2); # lop off the extra trailing comma
$query .= " WHERE {$id_field}={$newid}";
mysql_query($query);
// return the new id
return $newid;
}
Here is the link to the article http://www.epigroove.com/posts/79/how_to_duplicate_a_record_in_mysql_using_php
What about
insert into test.abc select null, val1, val2 from test.abc where val2 = some_condition;
Seems to work for me like that. Substitute your table, fields, condition of course.
The null lets the DB generate the auto-increment ID for you.
Options:
Avoid using the
*
wildcard, and specify all the columns yourself. But you say the table is expected to change in the future and this isn't a workable solution for your case.Introspect the columns from the current table definition (using
DESCRIBE
or by queryingINFORMATION_SCHEMA.COLUMNS
). Use this information about metadata to build the query, omitting the auto-increment primary key column.Do the
SELECT *
query, fetch the row back into your application, and then remove the auto-increment column from it. Then use that tuple to construct anINSERT
statement.
In short, you have a complex requirement to adapt to changing metadata. That probably can't be done in a single query.
How about copying the the rows into a temp table and then back into the customer table? I think that would force mysql to give it a new autoincrement ID, especially with the second version of the query you posted.
Two posts so far, and here is a 3rd option: In PHP, dynamically determine the fields in your table. Or, you can make an array list of fields that you "hard-code", maintain by hand to reflect the table. Your resulting query won't use *.
If you know the name of the primary key column in your table (and I'm guessing that you do because it's in the where clause anyway), I think you could do this:
Edit - I forgot that MySQL doesn't support select...into. This should work instead
create new_table
select *
from customer
where customerid = 9181
alter table new_table
drop column customerid
insert into customer
select null, *
from new_table
drop table new_table
There is an easy way, to create duplicate record in same table test. in my local
- Select column_name,data_type from information_schema.columns where table_name = 'your_table_name' AND column_name != 'id'
- Prepare the column_name array and join using "," to create an Insert statement like below
- INSERT INTO table2 (column1, column2, column3, ...) SELECT column1, column2, column3, FROM table1
- Perform Query insert . this will work easily
精彩评论