问题
I have a long script that I need to run on several different databases (all witht he same tables and field names).
What I would like to do is something like this:
1 SET @TARGET_DATABASE = 'beta'
2 SET @SOURCE_DATABASE = 'sandbox';
3
4 CREATE DATABASE IF NOT EXISTS @TARGET_DATABASE;
5 USE @TARGET_DATABASE;
...
10 INSERT INTO `tableFoo` SELECT * FROM @SOURCE_DATABASE.`tableFoo`;
On line 10 I get an error (I'm not surprised): "Script line: 10 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '@SOURCE_DATABASE.tableFoo' at line..."
So I tried this insted for line 10:
10 SET @TABLE=CONCAT('`',@SOURCE_DATABASE,'`','.`tableFoo`');
11 INSERT INTO `tableFoo` SELECT * FROM @TABLE;
...and again error "Script line: 11 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '@TABLE' at line..." As you can see, line 10 works fine...
Is there any way to refer to a table in a database with a variable?
// Thank you.
回答1:
It will work if you concat the entire query. Try:
set @db = 'mydb';
set @tble = 'table';
set @query = concat('INSERT INTO tablefoo SELECT * FROM ', @db, '.', @tble);
PREPARE stmt FROM @query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
来源：https://stackoverflow.com/questions/5530755/mysql-variables-storing-database-name