-1
votes
0answers
33 views

How can I delete duplications with one query? [closed]

Is there any way to delete duplications with one, or only two queries? I'm not good with SQL. Now I'm trying this solution: $le = mysql_query('SELECT * FROM tbl_answers'); while($i = ...
1
vote
1answer
48 views

Summation query with complex grouping criteria

I have a database of coded actions with this structure. {User, Date, ActionCode} I need to generate reports based on dates and action codes, and the action codes are not clean because we have to ...
2
votes
2answers
314 views

How do I remove duplicate records in a join table in PostgreSQL?

I have a table that has a schema like this: create_table "questions_tags", :id => false, :force => true do |t| t.integer "question_id" t.integer "tag_id" end ...
5
votes
2answers
105 views

Resolving DUPLICATE for a column with UNIQUE

I have a few column with UNIQUE INDEX. In some queries, duplicates should be acceptable, in which a postfix should be added to the value. For example, if test title exits, we change it to test ...
4
votes
2answers
158 views

MySQL check duplicate with group by using wildcard?

+----+--------------+-----+-----------+----------+ | ID | NAME | AGE | ADDRESS | SALARY | +----+--------------+-----+-----------+----------+ | 1 | Ramesh Olive | 32 | ...
1
vote
1answer
976 views

How to use ON DUPLICATE KEY for UPDATE

Consider a table of CREATE TABLE test ( id int(11) unsigned NOT NULL AUTO_INCREMENT, external_id int(11), number smallint(5), value varchar(255), UNIQUE INDEX (external_id, number), PRIMARY KEY(id) ...
2
votes
4answers
566 views

Two-sided UNIQUE INDEX for two columns

Creating a table with composite PRIMARY KEY or using UNIQUE INDEX for two columns guarantee uniqueness of col1, col2. Is there a tricky approach to make the reverse order of two columns UNIQUE too ...