creating a mysql table from a inner join

问题

I'm trying to create a mysql table from the inner join between two other tables. I'm dealing with a database someone creates which has the following tables:

• sitematrix_sites
• sitematrix_databases

They are related by another table (I don't know why don't use a foreign key) called sitematrix_sites_databases which has the following fields: site_id and database_id.

That's how the two tables relate. Now I'm trying to remove that to make my life easier, so I have:

mysql> CREATE TABLE result AS(select * from sitematrix_databases INNER JOIN site
matrix_site_databases ON sitematrix_site_databases.database_id = sitematrix_data
bases.database_id);
ERROR 1060 (42S21): Duplicate column name 'database_id'

However, I'm getting that error. Does someone know how can I merge the two tables without repeating the database_id field?

Thanks

回答1:

Remove the * in your SELECT statement and actually list out the columns you want in your new table. For columns that appear in both original tables, name the table as well (e.g. sitematrix_databases.database_id).

回答2:

Don't use * instead name each column and use aliases. For instance instead of sitematrix_database.database_id you can have alternativeName. Also you can pick and choose which columns you want this way as well.

回答3:

In SQL Server, you can use "select into". This might be equivalent syntax for mySql:

• http://dev.mysql.com/doc/refman/5.0/en/ansi-diff-select-into-table.html

Unfortunately, it's a two commands (not just one):

• http://www.tech-recipes.com/rx/1487/copy-an-existing-mysql-table-to-a-new-table/

CREATE TABLE recipes_new LIKE production.recipes; INSERT recipes_new SELECT * FROM production.recipes;

回答4:

Instead of using SELECT * ... try SELECT database_id ...

MySQL does not like joining tables that have the same column name.

来源：https://stackoverflow.com/questions/11040538/creating-a-mysql-table-from-a-inner-join