I have a table with 2 primary keys(user_id,post_id)
I want to insert row only if table havn't a row with this user id and post id
And if previous data exist for this keys , only that row update with the new data
I wrote this query:
INSERT INTO trust_list(`user_id`,`post_id`,`post_per`,`comment_per`,`cat_per`)
VALUES (7,1,'000','000','000')
ON DUPLICATE KEY UPDATE `post_per`='000',`comment_per`='000',`cat_per`='000'
For example if this row exist in the table:
user_id:5
post_id:1
post_per:001
comment_per:111
cat_per:101
Then ,when i execute the above query , mysql update this row,only because post_id of this row is "1"
Whereas mysql should not update this row .
I don't understand what's the problem.
DESC trust_list
result of above query is:
Field Type Null Key Default Extra
user_id int(11) NO PRI NULL
post_id int(4) NO PRI NULL
post_per tinytext YES NULL
comment_per tinytext YES NULL
cat_per tinytext YES NULL
=================
Thanks to all of my friends
When i decide to drop table and ceate it again ,I get an export from this table
and review the .sql file,i see this:
CREATE TABLE IF NOT EXISTS `trust_list` (
`user_id` int(11) NOT NULL,
`post_id` int(11) NOT NULL,
`post_per` tinytext COLLATE utf8_estonian_ci ,
`comment_per` tinytext COLLATE utf8_estonian_ci ,
`cat_per` tinytext COLLATE utf8_estonian_ci ,
PRIMARY KEY (`idea_id`,`user_id`),
UNIQUE KEY `idea_id` (`idea_id`)
)
apparently , problem is from the UNIQUE KEY ,I remove it from file ,and then drop trust_list table ,and then import .sql file
So with this ,my problem solved
Thanks again
There is something wrong with your table schema.
Assuming that your schema defined something like this
CREATE TABLE trust_list(
`user_id` int,
`post_id` int,
`post_per` varchar(12),
`comment_per` varchar(12),
`cat_per`varchar(12),
PRIMARY KEY(`user_id`, `post_id`)
);
here is SQLFiddle that demonstrates that your INSERT statement works on it just fine.
Consider to show your CREATE TABLE statement to help you find the problem, or just change PK as showed.
I think your problem is your understanding of primary key. You can't have two primary keys in the table, only one. What you have probably is a primary key that consists of two columns. In that case you only get a key violation when both columns match.
Solution:
Introduce unique indices for both columns. Or - better - change the primary key to be only one of the two columns and set the other column to have a unique index.
Thanks to peterem here is the sqlfiddle with my solution.
Related
I'm learning SQL.
I'm trying to insert data. My MySQL database looks like this.
CREATE TABLE category (
category_id CHAR(100),
category_name VARCHAR(120) NOT NULL,
PRIMARY KEY (category_id)
)
I ran this command
INSERT INTO category (category_name) VALUES ("test");
But I got this error
ERROR 1364 (HY000): Field 'category_id' doesn't have a default value
Thank you in advance.
If you want to have an incrementing ID it would need to be an int. You Generally want to make ID's integers not chars to speed up lookup regardless.
CREATE TABLE IF NOT EXISTS category (
`category_id` INT NOT NULL AUTO_INCREMENT,
`category_name` VARCHAR(120) NOT NULL,
PRIMARY KEY (`category_id`)
) ENGINE=InnoDB DEFAULT CHARSET = utf8mb4 COLLATE utf8mb4_unicode_ci;
That will let you insert without adding your own ID, and automatically generate unique ID's for the records.
Issue was you set your category_id field to not have a default value and also not allow null, which means you -have- to set a value for it in the insert. If you wanted to use your existing table you would need to do this:
INSERT INTO category (category_id, category_name) VALUES ("someid", "test");
I want to create a table name Users where I should have have columns User, cookieID, sessionID, Geo and then I want to first three columns to have some random unique value assigned automatically. I tried to make all three columns AUTO_INCREMENT with User column PRIMARY and 'cookieIDandsessionIDcolumnUNIQUE`. The SQL code is:
CREATE TABLE `users` ( `User` VARCHAR(20) NOT NULL AUTO_INCREMENT ,
`cookieID` INT(20) NULL DEFAULT NULL AUTO_INCREMENT ,
`sessionID` INT(20) NULL DEFAULT NULL AUTO_INCREMENT ,
`Geo` VARCHAR(30) NULL DEFAULT NULL ,
PRIMARY KEY (`User`), UNIQUE (`cookieID`), UNIQUE (`sessionID`), UNIQUE (`Geo`));
But, it did not work because only one column can be declared as AUTO_INCREMENT which must be PRIMARY.
What is the another approach to do this?
Since the auto-increment cannot be applied to multiple to rows and there no option for sequence in MySQL. You can use triggers for the unique update of the row with datetime.
Change to table creation to be of single auto-increment row.
CREATE TABLE `users` ( `User` VARCHAR(20) NOT NULL,
`cookieID` INT(20) NULL DEFAULT NULL,
`sessionID` INT(20) NULL DEFAULT NULL AUTO_INCREMENT ,
`Geo` VARCHAR(30) NULL DEFAULT NULL,
PRIMARY KEY (`User`), UNIQUE (`cookieID`), UNIQUE (`sessionID`), UNIQUE (`Geo`));
Create a trigger on the same table as below. You can set the unique values under the SET for as many column as you want.
CREATE DEFINER=`root`#`localhost` TRIGGER `users_BEFORE_INSERT` BEFORE INSERT ON `users` FOR EACH ROW BEGIN
SET
NEW.cookieID = (SELECT curdate()+curtime());
END
Now when you insert into the table as below.
insert into `users`(`User`) values("test");
You table looks like this.
User cookieID sessionID Geo
test 20315169 0 NULL
If the value which are auto incrementing, you wanna keep both values the same. Then copy the value of one column to another during insertion time of new value.
Sorry if this is an easy question, I am coming to MySQL from SQL Server.
When I execute my create statement it contains nvarchar but commits to the database as varchar. Even in my alter statement afterwards the column does not change at all. Does the collation or DB engine make a difference?
During execution I am not encountering any issues in results, other than the fact the column changes datatype. I attached a screencast of my activity http://screencast.com/t/wc94oei2
I have not been able to find anyone with similar issues through my Google searches
Did you mean, this..
CREATE TABLE stars (
idstars int(11) NOT NULL AUTO_INCREMENT,
Name nvarchar(200) DEFAULT NULL,
PRIMARY KEY (idstars),
UNIQUE KEY Name_UNIQUE (Name)
)
----turns to---
CREATE TABLE stars (
idstars int(11) NOT NULL AUTO_INCREMENT,
Name varchar(200) DEFAULT NULL,
PRIMARY KEY (idstars),
UNIQUE KEY Name_UNIQUE (Name)
)
I would like to create some tables in MySQL. One table would be for users, one for topics, one for comments, and so on.
I need each table to have its own ID column in the following format:
USERS table: ID column
Values:
USR00001
USR00002
USR00003
..
..
USR99999
where as topics table would have IDs like:
TPC00001
TPC00002
TPC00003
similarly, the comments table would have the following IDs:
CMT00001
CMT00002
I tried to use UNIQUE key but did not work: (inspired by this answer)
CREATE TABLE `users` (
`ID` BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT ,
`firstname` VARCHAR(100) NOT NULL ,
`lastname` VARCHAR(100) NOT NULL ,
`email` VARCHAR(100) NOT NULL ,
PRIMARY KEY (`ID`)
UNIQUE KEY ( 'USR' + `ID`)
);
Can it be done using triggers (Before Insert) maybe?
Please note that I don't want to handle the insertion of the primary keys on the application level. I would prefer the database engine to handle all the work for that.
I have a table in which there is a column name with SP varchar(10) NOT NULL. I want that column always to be unique so i created unique index on that column . My table schema as follows :
CREATE TABLE IF NOT EXISTS `tblspmaster` (
`CSN` bigint(20) NOT NULL AUTO_INCREMENT,
`SP` varchar(10) NOT NULL,
`FileImportedDate` date NOT NULL,
`AMZFileName` varchar(50) NOT NULL,
`CasperBatch` varchar(50) NOT NULL,
`BatchProcessedDate` date NOT NULL,
`ExpiryDate` date NOT NULL,
`Region` varchar(50) NOT NULL,
`FCCity` varchar(50) NOT NULL,
`VendorID` int(11) NOT NULL,
`LocationID` int(11) NOT NULL,
PRIMARY KEY (`CSN`),
UNIQUE KEY `SP` (`SP`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=10000000000 ;
Now i want that if anybody tries to insert duplicate record then that record should be inserted into a secondary table name tblDuplicate.
I have gone through this question MySQL - ignore insert error: duplicate entry but i am not sure that instead of
INSERT INTO tbl VALUES (1,200) ON DUPLICATE KEY UPDATE value=200;
can i insert duplicate row into another table ?
what changes needed to be done in main table scheme or index column ?
**Note : Data will be inserted by importing excel or csv files and excel files generally contains 500k to 800 k records but there will be only one single column **
I believe you want to use a trigger for this. Here is the MySQL reference chapter on triggers.
Use a before insert trigger. In the trigger, check if the row is a duplicate (maybe count(*) where key column value = value to be inserted). If the row is a duplicate, perform an insert into your secondary table.