Add IGNORE to the statement, then use SELECT to have a look at the table contents to see how the duplicates ha : Alter Table « Table Index « SQL / MySQL






  1. SQL / MySQL
  2. Table Index
  3. Alter Table

Add IGNORE to the statement, then use SELECT to have a look at the table contents to see how the duplicates ha

      
ve been removed:
mysql>
mysql> CREATE TABLE mytbl
    -> (
    ->    i INT,
    ->    c CHAR(1)
    -> );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>
mysql> ALTER IGNORE TABLE mytbl ADD UNIQUE (i,c);
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql>
mysql> drop table mytbl;
Query OK, 0 rows affected (0.00 sec)








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36.Alter table to Delete an Index
37.Alter table to add index
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