If that source happens to be other tables within the same database, then My SQL has got you covered. SELECT” statement, which selects the fields from one table and inserts them into another.For instance, the following statement will take all the records from table1 and insert them into table2: As the name suggests, I’d like to store the most expensive rentals in their own table. Using the INSERT…SELECT statement, we can populate all of the fields except for the id, which is an AUTO_INCREMENT type: Since the primary key is not being inserted in the above example there is nothing stopping duplicate records from being created. Of course you will have to supply the id value as well or the record will never be a duplicate!Even with a lot of experience under your belt as a Database Administrator (DBA), using Insert and Update statements can be a nerve racking affair.I know that every time I run one of these commands on a production database I have to hold my breath as I click the php My Admin GO button.I have to start with one spreadsheet, then insert and/or update the differences from the others.What I want to do is either insert only the new rows, or insert the new rows and update the changed rows (depending on the scenario). If I want to insert only the rows that will not violate the unique index, I can: Which method to use largely depends on requirements.
There are, in fact, two separate sets of ISO codes, 2-letter and 3-letter, so you may not in reality be able to join these columns: ISO 3166-1 The join condition There is a difference in behavior to my version - your version will set it to NULL if it's not found, mine will not alter an existing value if it's not matched. Also the execution plan may differ depending upon the [email protected] It's probably not a problem - when you add the new column, I'm assuming it will be NULL and also a foreign key, so invalid entries wouldn't be allowed anyway.This isn't necessarily a very realistic example as you would be more likely to want to straight out delete the non-matching entries or use a select query instead to display them in a list for editing but it illustrates how it can be done.The article about how to delete records with My SQL using a cross join uses these examples to delete instead of update.Fluency with SQL is necessary for effective communication with the My SQL server, because that is the language that it understands.For example, when you use a program such as the mysql client, it functions primarily as a means for you to send SQL statements to the server to be executed.