Mysql on duplicate key update multiple values

We have a dynamic query that inserts data from a CSV file, what we want is to update all the rows even if there are duplicates. We know that this works: INSERT INTO. On Duplicate Key Update - Multiple Columns. ON DUPLICATE KEY UPDATE.

In our student table we have one unique auto increment field as ID. Now, when using INSERT on DUPLICATE KEY UPDATE , we need to specify the criteria that the database needs to check in order to decide if it should update or insert. We need a unique key , and MySQL allows us to specify multiple columns via a composite key , which uniquely indentifies an entity occurrence. The statement above sets the value of the cto its current value specified by the expression VALUES (c1) plus if there is a duplicate in UNIQUE index or PRIMARY KEY.

This function is especially useful in multiple -row inserts. Now I would like to add a trigger which does the following: if NEW. Please give me direction.

On duplicate key update multiple values MYSQL. I am using MySQL version 5. I have detailed the unexpected behavior below. Sometimes, when updating on duplicate key it comes in handy to use VALUES () in order to access the original value that was passed to the INSERT instead of setting the value directly. This way, you can set different values by using INSERT and UPDATE.

See the example above where other_field_is set to insert_ value on INSERT or to update _ value on. How to make multiple updates using a single query in MySQL. MySQL reports values for the number of rows affected. When an operation affects rows in multiple tables, or when a duplicate row causes an update to existing values , the rows-affected statistics change in odd ways.

Anyway to pull off an on duplicate key update for an insert statement with MySQL ? Conditional duplicate key updates with MySQL. In one of our larger Rails apps the sheer volume of data we process means we’ve had to rely more and more on direct SQL queries, denormalised tables and summary tables to speed things up. Obwohl ich sehr spät INSERT-SELECT bin, aber nachdem ich einige legitime Fragen für diejenigen gesehen habe, die eine INSERT-SELECT Abfrage mit der GROUP BY Klausel verwenden wollten, habe ich mir die Arbeit ausgedacht. MySQL UPDATE multiple columns MySQL UPDATE command can be used to update multiple columns by specifying a comma separated list of column_name = new_ value.

Where column_name is the name of the column to be updated and new_ value is the new value with which the column will be updated. The rows that cause errors such as duplicate - key conflicts are not updated. Let’s practice the UPDATE statement. Using MySQL UPDATE to modify values in a single column example.

See the following employees table from the sample database. How can I update the field values mentioned in the insert portion without listing them again in the on duplicate key update portion? This is also documented at the MySQL 5. Certification Study Guide: Chapter 11. CLAVE PRIMARIA o algún campo ÚNICO. Join Sheeri Cabral for an in-depth discussion in this video Updating values if they already exist with INSERT.

To insert multiple rows with a single query you can use regular insert with multiple value rows. You can also use update if you have primary key set. With it you use an INSERT instead of UPDATE but add the primary key for the query to check for unique values. This way you can add many thousand updates in one query. This does not happen when the INSERT.

Lets say the primary key for a table is an integer field and user executes an insert query by giving the value for the Id (Primary Key ) field as “1”. As MySQL doesn’t have inherent support for updating more than one rows or records with a single update query as it does for insert query, in a situation which needs us to perform updating to tens of thousands or even millions of records, one update query for each row seems to be too much. The table must have a UNIQUE key or PRIMARY key constraint defined which MySQL can use to check if duplicate value exists. Die Einträge mit doppelten Primärschlüsseln wurden nicht erstellt.

Dafür gibt es Primärschlüssel. Wenn Sie eins duplizieren müssen, sollte dieses Feld an erster Stelle kein Primärschlüssel sein. How do I update sets of duplicate values ,. The alternative (and generally preferred) method for INSERTING into rows that may contain duplicate UNIQUE or PRIMARY KEY values is to use the INSERT.

Unlike REPLACE – an inherently destructive command due to the DELETE commands it performs when necessary – using. It means that MySQL generates a sequential integer whenever a row is inserted into the table. The start_date, due_date, and description columns use NULL as the default value , therefore, MySQL uses NULL to insert into these columns if you don’t specify their values in the INSERT statement.

MySQL INSERT – Inserting rows using default value.