Duplicate entry for key 'PRIMARY' .Ignoring the spaces for strings

Question

mysql> CREATE TABLE primary2(boom text,id int,PRIMARY KEY(boom(5)) );
Query OK, 0 rows affected (0.04 sec)

mysql> INSERT INTO primary2 VALUES(\'viok\',1);
Que         


        

Answer 1

Q: How to add a string with spaces?

A: It's not possible.

The TEXT values 'viok' and 'viok ' are not unique, in terms of how MySQL stores those as index entries. This is documented behavior:

If a TEXT column is indexed, index entry comparisons are space-padded at the end. This means that, if the index requires unique values, duplicate-key errors will occur for values that differ only in the number of trailing spaces. For example, if a table contains 'a', an attempt to store 'a ' causes a duplicate-key error. This is not true for BLOB columns.

Answer 2

MySQL ignores trailing spaces in string comparisons. One way is to add a column to store number of trailing spaces the text has.

One way is to store it as varchar, which allows trailing spaces.