I have a little problem.
This is the SQL code I get:
INSERT INTO matches (match_id, league_name, league_id, test_one)
VALUES (866860, 'Portugal',1,'testing')
ON DUPLICATE KEY
UPDATE league_name =
CASE match_id
WHEN 866860
THEN 'Portugal' END,
league_id =
CASE match_id
WHEN 866860
THEN 1 END,
test_one =
CASE match_id
WHEN 866860
THEN 'testing' END
The problem is, that it always insert a new row instead of updating the existing one.
Is it because I need to make the "match_id" as AUTO_INCREMENT or anything else (at the moment, my "id" field is AUTO_INCREMENT)
AUTO_INCREMENT is irrelevant here. But ON DUPLICATE KEY requires a key. More specifically, a unique key, such as primary key or a unique index.
Given the column names, I suspect that match_id fails to be a primary key.
Update: You also write a complicate set of CASE ... END constructs. Have a look at the VALUES() function.
You are telling your database to update information "ON DUPLICATE KEY"; if none of the other fields are UNIQUE keys, the database will insert a new row.
You can either SELECT the id before this query (or making it a sub-query) or add another key to this table that will result in a unique value for each row. I don't know about your schema, but you might be able to create a multi-part key which spans match_id and league_id.
Related
I want to insert if in the table is not same row with values, but if there is row with the same values I want to only update one that will add +1 to the current value. I have current code, but it doesn't seem to update values in row that exists.
INSERT INTO raport(id, wykonawca, tytul, czas_trwania, powtorzenia)
VALUES('','$wykonawca2','$tytul2','$czas_trwania2', '$powtorzenia2')
ON DUPLICATE KEY UPDATE wykonawca='$wykonawca2', tytul='$tytul2', czas_trwania='$czas_trwania2',
powtorzenia='$powtorzenia2'+1
Ensure your table has a column declared as UNIQUE or PRIMARY KEY and is not an Auto-increment column
If you specify an ON DUPLICATE KEY UPDATE clause and a row to be inserted would cause a duplicate value in a UNIQUE index or PRIMARY KEY, an UPDATE of the old row occurs. For example, if column a is declared as UNIQUE and contains the value 1, the following two statements have similar effect:
INSERT INTO t1 (a,b,c) VALUES (1,2,3)
ON DUPLICATE KEY UPDATE c=c+1;
UPDATE t1 SET c=c+1 WHERE a=1;
(The effects are not identical for an InnoDB table where a is an auto-increment column. With an auto-increment column, an INSERT statement increases the auto-increment value but UPDATE does not.)
MySQL Reference
EDIT :
Your id column is empty you need to pass a value
The actual answer to your initial question as to why the rows do not update is because you are not passing a value for the PRIMARY KEY - this is your AUTO-INCREMENT id column.
Every time you pass :
VALUES('','$wykonawca2','$tytul2','$czas_trwania2', '$powtorzenia2')
this means that your id column is blank, so there is no duplicate just a new row. If you want to have an ON DUPLICATE KEY UPDATE you'll need to pass in the id.
For some more info about ways to handle multiple indexes and DUPLICATE UPDATE check this question out: MySQL behavior of ON DUPLICATE KEY UPDATE for multiple UNIQUE fields
Also, you should read this and action it as soon as possible, you shouldn't be passing variables straight into sql - it's hugely outdated and very unsafe:
How can prepared statements protect from SQL injection attacks?
I want to add complex unique key to existing table. Key contains from 4 fields (user_id, game_id, date, time).
But table have non unique rows.
I understand that I can remove all duplicate dates and after that add complex key.
Maybe exist another solution without searching all duplicate data. (like add unique ignore etc).
UPD
I searched, how can remove duplicate mysql rows - i think it's good solution.
Remove duplicates using only a MySQL query?
You can do as yAnTar advised
ALTER TABLE TABLE_NAME ADD Id INT AUTO_INCREMENT PRIMARY KEY
OR
You can add a constraint
ALTER TABLE TABLE_NAME ADD CONSTRAINT constr_ID UNIQUE (user_id, game_id, date, time)
But I think to not lose your existing data, you can add an indentity column and then make a composite key.
The proper syntax would be - ALTER TABLE Table_Name ADD UNIQUE (column_name)
Example
ALTER TABLE 0_value_addition_setup ADD UNIQUE (`value_code`)
I had to solve a similar problem. I inherited a large source table from MS Access with nearly 15000 records that did not have a primary key, which I had to normalize and make CakePHP compatible. One convention of CakePHP is that every table has a the primary key, that it is first column and that it is called 'id'. The following simple statement did the trick for me under MySQL 5.5:
ALTER TABLE `database_name`.`table_name`
ADD COLUMN `id` INT NOT NULL AUTO_INCREMENT FIRST,
ADD PRIMARY KEY (`id`);
This added a new column 'id' of type integer in front of the existing data ("FIRST" keyword). The AUTO_INCREMENT keyword increments the ids starting with 1. Now every dataset has a unique numerical id. (Without the AUTO_INCREMENT statement all rows are populated with id = 0).
Set Multiple Unique key into table
ALTER TABLE table_name
ADD CONSTRAINT UC_table_name UNIQUE (field1,field2);
I am providing my solution with the assumption on your business logic. Basically in my design I will allow the table to store only one record for a user-game combination. So I will add a composite key to the table.
PRIMARY KEY (`user_id`,`game_id`)
Either create an auto-increment id or a UNIQUE id and add it to the natural key you are talking about with the 4 fields. this will make every row in the table unique...
For MySQL:
ALTER TABLE MyTable ADD MyId INT AUTO_INCREMENT PRIMARY KEY;
If yourColumnName has some values doesn't unique, and now you wanna add an unique index for it. Try this:
CREATE UNIQUE INDEX [IDX_Name] ON yourTableName (yourColumnName) WHERE [id]>1963 --1963 is max(id)-1
Now, try to insert some values are exists for test.
I have a mysql on duplicate key statement.
mysql_query("INSERT INTO statistics (classify, apply) VALUES ('$classify', 1)
ON DUPLICATE KEY UPDATE apply = apply + 1");
id classify apply
1 A 1
but it didn't update the existing row and it keep add another row, Where is the problem?
It's probably the column classify is not unique. You need to have a UNIQUE field in the table to make ON DUPLICATE KEY UPDATE work. If you have not set one, you can execute this statement below.
ALTER TABLE statistics ADD CONSTRAINT tb_uq UNIQUE (classify)
ON DUPLICATE KEY will update a row only when you try to insert a record that would throw a duplicate keys error (like the name states). So this happens only if you are a using a unique key or a primary key for that column. It looks like you didn't created a unique key for the classify column.
I'm creating a messaging system and I'm trying to set it up so it will have a "conversation view" and so users can reply to a message. To do this I have to have a primary ID for each conversation in the table and then a separate unique ID for each message.
My problem is that when I try replying to a message I get this error:
Duplicate entry '98' for key 1
It looks like it isn't allowing me to use the same ID in a column, but I don't have a 'unique' thing set in the table AFAIK.
I also tried to drop the PRIMARY for the id column but got this error:
The message is:
#1075 - Incorrect table definition; there can be only one auto column and it must be defined as a key
I don't understand why it won't let me insert the same ID into the id column, because as you know I need an ID for each conversation.
The mysql_query that I'm using to insert the reply into the table is:
$sql = "INSERT INTO messages (id, message_id, to_user, message, subject, from_user, date, time, date_short)
VALUES ('$id', '$message_id', '$to', '$message', '$subject', '$user', '$date', '$time', '$date_short')";
mysql_query($sql) or die(mysql_error());
Thanks in advance!
Your primary key can not be repeated, otherwise it isn't so useful as a key, is it? The primary key must uniquely identify the record.
The reason you're getting the error is that the column is set to be auto-number. You have not added that column to a separate key, which is a requirement for auto-number columns in MySQL.
Add it to a key/index with that column first, then remove the PK attribute. Make sure you have some PK in the table.
You can't have auto_increment without a key
I suspect you have AUTO_INCREMENT setup on your id field. If this is the case, then the values in the id column must be unique.
Either remove the AUTO_INCREMENT attribute on that column (by redefining the column without AUTO_INCREMENT via an ALTER TABLE command), or don't specify the id value in your INSERT statement.
First, untick AUTO_INCREMENT option on your column and as the second step, try to drop the index again
PRIMARY KEYs are also unique. auto_increment columns must be primary keys. You can't drop PRIMARY KEY from a column without making it not auto_increment.
However, I don't think you should change your table like this. You should keep your IDs and either create a new table with the data you need to update, or use UPDATE instead of INSERT.
Columns with primary keys can't have duplicates, otherwise they lose their uniqueness. MySQL will prevent same values. Having to alter primary key vales is also bad news. You may want to re-approach what you're doing and possibly create more tables.
I want an id and name to be primary key for my table. I want to increment id with every insert, so i set it to auto_increment. The problem is when i insert into table a new entry with same name, it inserts it with a new id and there are duplicate entries with same name and different ids. I don't want to search the table beforehand to see if there is any entry beforehand. Please help me how to correct this problem.
I think you have done something like this
CREATE TABLE table1
id unsigned integer autoincrement,
name varchar,
....
primary key (id,name)
This primary key does not select on unique name, because the autoincrement id will always make the key as a whole unique, even with duplicate name-fields.
Also note that long primary keys are a bad idea, the longer your PK, the slower inserts and selects will execute. This is esspecially bad on InnoDB, because the PK is included in each and every secondary key, ballooning your index files.
Change it to this
CREATE TABLE table1
id unsigned integer autoincrement primary key,
name varchar,
....
unique index `name`(name)
If you want it to be unique by name, you need to add a unique index on the name field, and then you can use the mysql syntax for on duplicate key: mysql reference for on duplicate key
You could apply a unique index to your name field, or if you're storing people, allow duplicate names.
Add UNIQUE(your_column_name) where you should replace your_column_name with the column in your database.