I am new to MySQL databases and I have just imported my Access database into MySQL. When I did so, my primary key (ID) filed for one particular table is a bit messed up.
I would like all primary keys to be a number, but there is on that is showing up as a the height of a person. This is not present in the Access database.
I would add a picture but I cannot because I do not have the reputation yet... There is a 5' 7" in the ID place of an actual ID. When I attempt to delete this entry using the command
DELETE FROM actor_demographics WHERE ID=5' 7";
I am not able to delete the ID key.
Any ideas?
DELETE FROM actor_demographics WHERE ID=5' 7";
Is MySQL incorrect, it should be
DELETE FROM actor_demographics WHERE ID="5' 7\"";
It seems likely your ID column has a stringlike, not numberlike, data type.
Try using a string literal in your DELETE statement, thus
DELETE FROM actor_demographics WHERE ID='5'' 7"';
Because you need a ' character in your string constant, double it to escape it.
Related
I have seen this error with people running php scripts before but this is happending to me in phpmyadmin ??
Error
SQL query:
UPDATE `cl56-goldeng`.`users` SET `email` = '' WHERE `users`.`id` =118
MySQL said: Documentation
#1062 - Duplicate entry '' for key 'email'
It works fine if I give the field another value, but if I clear the field and press enter I get the above error.
The table itself looks like this :
On your table cl56-goldeng.users, the field email was specified on creation to not allow more than 1 of the same value to be allowed into it. This is done using the UNIQUE identifier on table creation in MySQL. You can see more on the UNIQUE identifier at this link.
You have 2 options that you could go about doing.
First would be to remove the unique constraint on the email field. This entirely depends on your logic in your code, but seeing as emails should almost always be unique, this is not suggested.
You can drop a unique key by running the command:
alter table [table-name] drop index [unique-key-index-name];
Second, would be to use NULL instead of an empty string. My assumption is that you are setting an empty string when the users email does not exist. In this scenario, it would be better to use NULL, and then check for that when retrieving data from the database.
You can insert a NULL value by using the NULL identifier in your MySQL statement, like such:
INSERT INTO users (firstName,lastName,email)
VALUES ('Bob','Ross',NULL);
And then check for a NULL value in whatever language you are accessing this data from.
You have a unique constraint on your email field. Either rethink your logic or drop the unique constraint.
Thats because you may have declare the email as unique key, and once you enter one row of empty email, it wont except another empty email
I have an app that has to import TONS of data from a remote source. From 500 to 1500 entries per call.
Sometimes some of the data coming in will need to replace data already stored in the dB. If I had to guess, I would say once in 300 or 400 entries would one need to be replaced.
Each incoming entry has a unique ID. So I am trying to figure out if it is more efficient to always issue a delete command based on this ID or to check if there is already an entry THEN delete.
I found this SO post where it talks about the heavy work a dB has to do to delete something. But it is discussing a different issue so I'm not sure if it applies here.
Each incoming entry has a unique ID. So I am trying to figure out if it is more efficient to always issue a delete command based on this ID or to check if there is already an entry THEN delete.
Neither. Use INSERT ... ON DUPLICATE KEY UPDATE ....
Since you are using MySQL and you have a unique key then let MySQL do the work.
You can use
INSERT INTO..... ON DUPLICATE KEY UPDATE......
MySQL will try to insert a new record in the table, is the unique value exists in the table then MySQL will update all the field that you have set after the update
You can read more about the INSERT INTO..... ON DUPLICATE KEY UPDATE...... syntax on
http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html
I am using cfwheels (coldfusion orm framework).
I recently moved some data from my previous host to a new one. Now I am trying to insert into a table, but am getting an error message: "Error Executing Database Query.
Duplicate entry '13651' for key 'PRIMARY'"
I looked into the database and it appears a record with id 13651 already exists. So I think the problem is with mysql generating the right auto increment value.
It seems Auto_Increment value is damaged or not set to max value in that column. It's possible due to bulk insert.
So as per solution, set the maximum PK value + 1 as new AUTO_INCREMENT value. Now when you insert the records in this table, they will automatically pick the next incremented correctly.
ALTER.TABLE tablename AUTO_INCREMENT = value
Is the rest of the data for that record, and the one you are trying to insert, the same? If you you might just need to tell the ORM to replace that value?
If primary key has auto increment attribute turned on, do not insert it manually. remove that primary key part from your insert query (whatever the syntax according to the taste of your ORM framework).
I'm trying to reset the seed for an autoincrement field in SQLITE using AIR/ActionScript/Flex 4.5.
I'm doing what should normally work:
DELETE FROM SQLITE_SEQUENCE WHERE NAME = 'myTable'
I've checked that the database actually contains a SQLITE_SEQUENCE table. I'm able to execute the above statement without errors directly via the Firefox SQLITE plugin (SQLite Manager).
However, when I try to do the same using actionscript, I get an error:
No such table 'SQLITE_SEQUENCE'.
All I could find in searching around was this one guy who posted everywhere he could find - only to be left without an answer:
here
and
here
and
here
Any ideas?
sqlite_sequence table is not created, until you define at least one autoincrement and primary key column in your schema.
You should to insert "Auto increment" to primary key column
at least to one table,
Then SQLite is creating "SQLITE_SEQUENCE" table.
To get all tables have Auto increment:
SELECT * FROM SQLITE_SEQUENCE;
I have a table that is in production. I realize that some of the columns should be unique. Is it safe to go into phpMyAdmin and change those columns to make it unique?
ALTER TABLE `foo` ADD UNIQUE ( `bar` )
Follow the below steps to apply unique column value from phpmyadmin panel:
Go to the table structure. Click on the unique keyword as like below -
Click on the ok from confirmation box -
Unique value constraint for column will apply.
Or you can run mysql query:
ALTER TABLE user ADD UNIQUE(email);
You do not have duplicates -> will apply the key without issues
You do have duplicates -> will give an error message, nothing happened to your data
All is unique, except several rows with NULL in them, unique constraint is still applied, as NULL is not checked when checking for unique values (you can have the entire table have a NULL value in a unique field without any error message).
One more thing, if you have a prod DB, you must also have a dev DB which you can test on without fear, right?
If there are already some duplicate values in those columns, then this will generate an error. If there aren't any duplicate values in those columns, then you will be fine.
It will only be a problem if the pre-existing values on the table are not unique, otherwise I don't think there will be any problem.
I had this problem and my values were not unique. I also couldn't find an easy way to edit this problem in PHPMyAdmin. Here's how I solved it:
I clicked into the table I needed to update
I exported the table, changing it to be a CSV export and then edited
it manually to update the non-unique values.
Making sure I was still in the table I had exported (because I
wanted to keep the headers intact), I imported my newly saved CSV
Hope that saves someone some time in the future.