I've been fighting to get the SQL right on this insert statement.. here's what I'm trying to do:
I have new empty table that has a 1-to-1 relationship with another table. Since all the other columns have default values I only want to insert the primary key column as new rows from the old table. Table names are dealer and dealer_nav and the fields are id and dealer_id respectively.
Thanks!
INSERT INTO dealer_nav(dealer_id) SELECT id FROM dealer (or vice versa, I'm not sure which of 2 tables is new and which is old)
Related
I have an existing table of products, and I'm trying to insert new attributes from other tables into my main product table.
Here's my query:
INSERT INTO company_attributes (amp)
SELECT company_attr_amperage.amp
FROM company_attr_amperage
INNER JOIN company_attributes
ON company_attr_amperage.product_id = company_attributes.product_id;
The error that I get is: Field 'product_id' doesn't have a default value.
I'm not trying to insert into the product_id column, I'm trying to insert into the amp column (as specified on row 1 of the query)
The amp column exists on the company_attributes table, but right now, every value is NULL
Thanks
You may just want to update the value in existing rows. If so:
UPDATE company_attributes ca JOIN
company_attr_amperage caa
ON caa.product_id = ca.product_id
SET ca.amp = caa.amp;
INSERT's job is to put new rows into a table, in your case company_attributes. Those new rows must be valid. Your table definition says that there's no default value for a column called product_id in that table. So, MySQL doesn't know what to put into that column when you don't provide it with your INSERT operation.
So, when you insert a row you must provide a value for that column.
There's no way to put a value into a column without creating a row for it, or UPDATEing an existing row.
INSERT INTO trees (preview)
select galleries.preview
from galleries,trees
where trees.id=galleries.idTree;
I am trying to move a column from a table to another, I have set an empty column with the same data type as the original.
Where idTree is equal to id to the destination table (in the source table idTree is foreign key reference to id on trees that is the destination).
The "select" works and give me back the right set of values (at least ordered by id and all) but the insert into part, do nothings and the field on trees is still empty. what am I doing wrong ?
INSERT INTO.. will create a new row; but you are looking to update the existing rows in trees table which has id. Try with UPDATE query instead:
UPDATE trees
JOIN galleries ON galleries.idTree = trees.id
SET trees.preview = galleries.preview
Part 1:
In MySQL suppose I have Table A which has more columns than Table B. I want to transfer values from Table B to Table A where the id row in A matches the id Row in B and update the values in table A from the values in table B.
Part 2:
Table B is a superset of table A, so how does one insert ids and their corresponding values from table B into table A while also updating id's that are in table A.
Like FreshPrinceOfSO already mentioned in the comments, you won't get code for free here.
But here are at least the steps. Two possibilities. Either you split the work up in two statements, one update then one insert statement. Or you could work with
INSERT ... ON DUPLICATE KEY UPDATE ...
You would have to have an unique index on the table for this to work.
For the first solution mentioned you'd inner join the tables for the update first, that's trivial. Then for the insert you'd use a select with a left join and with is null checking for entries that are not already in the table.
Good luck...
Here is the scenario:
I have 2 tables and 2 temporary tables. Before I insert user data to the official tables, I insert them to a temp table to let them do the checks. There is a company table with company info, and a contact table that has contact info. The contact table has a field called company_id which is a foreign key index for the company table.
Temp tables are set up the same way.
I want to do something like: INSERT INTO company () SELECT * FROM temp_company; and INSERT INTO contact () SELECT * FROM temp_contact
My question is, how do I transfer the foreign key from the temp_company to the newly inserted id on the company table using a statement like this? Is there a way to do it?
Currently I am:
grabbing the temp rows
going one by one and inserting them
grabbing the last insert id
then inserting the contacts afterwards with the new last insert id
I just don't know if that is the most efficient way. Thanks!
if you have the same number of columns in both tables and then you should just be able to use the syntax you have there? Just take out the (). Just make sure there aren't any duplicate primary keys:
INSERT INTO company SELECT * FROM temp_company;
INSERT INTO contact SELECT * FROM temp_contact;
You can also specifically specify the columns that get inserted, this way you can specify exactly which column you insert as the new ID.
INSERT INTO company (`ID`,`col_1`,...,`last_col`) SELECT `foreign_key_col`,`col_1`,...,`last_col` FROM temp_company;
INSERT INTO contact (`ID`,`col_1`,...,`last_col`) SELECT `foreign_key_col`,`col_1`,...,`last_col` FROM temp_contact;
Just make sure you are selecting the right # of columns.
Let's say I have a table, category, which has 3 columns, id, parent_id and name.
I have several tables like this, and I want to consolidate them into one. At present, their IDs will clash (not unique across DBs) so I need to re-ID them. If I make id an auto_increment I can copy all the other columns over just fine, but then parent_id won't link up properly anymore. Is there some magical way I can get the parent_id to point to the correct new ID?
Looking for something like
INSERT INTO newtable (parent_id, name) SELECT ???, name FROM oldtable
How about
Generate a new table with a column containing the name of the old table and old id (oldid, oldtablename) along with a new ID
Add a new column 'newparentid'
Update each row's newparentid to be (SELECT newid FROM newtable nt WHERE oldtablename = row.oldtablename and nt.oldid = row.parent_id)
I imagine you could add an old_id column so that you'll still have the original id and you can run successive updates to the table to modify all the parent_ids to point to the new auto_inc ids. You would obviously have to kill any foreign keys requirements on the table first and reinstitute them after all the changes were made – Patrick