![]() REPLACE INTO table_name (column1, column2, lumnN) Syntaxįollowing is the syntax of the REPLACE statement of MySQL. In the case of the REPLACE statement if you try to insert a new column with duplicate value for the column with UNIQUE or PRIMARY KEY constraints the old record will be completely replaced by the new record. While inserting a record using the insert statement if a column has a UNIQUE or PRIMARY KEY constraint, if the new record has same value for this column an error will be generated. The replace statement is similar to the INSERT statement using this you can insert records into the specified table. In this, you need to specify the name of the table, column names, and values. Should any right be infringed, it is totally unintentional.ĭrop me an email and I will promptly and gladly rectify it.You can add new rows to an existing table of MySQL using the INSERT statement. Registered trademarks of their respective companies. Software and hardware names mentioned on this site are No portion may be reproduced without my written permission. Update multiple rows (distinctive by primary key) for multiple columns in one queryĬopyright © 2023. Update multiple rows (distinctive by primary key) with different values in one queryġ2. Combine update and insert into one statementġ1. How to create and use AUTO_INCREMENT column and use LAST_INSERT_ID functionġ0. How to do cross-table update in MySQL - Part 2ĩ. How to do cross-table update in MySQL - Part 1Ħ. How to update top N rows of data in MySQLĥ. How to update data in a specific order in MySQLģ. REPLACE INTO email_sent_count ( Email, SentCount, SentTime, HashValue ) ID column is auto increment which is also unique, but checking if a record exists is based on email column ratherĮmail address already exists in the table, so it will trigger a delete (ID 2 will be deleted), then ID 5 will be inserted. INSERT.ON DUPLICATE KEY UPDATE instead of REPLACE. ![]() REPLACE INTO is a very slower operation because it involves both delete and insert.īased on the side effects listed above, you should consider using.If you have DELETE triggers in the table, they would be fired automatically and may have unexpected effect on the table.If you need to maintain history of changes for the records, don't use REPLACE because the matched row is deleted.If the primary key table has cascading foreign keys (a foreign key constraint ON DELETE CASCADE), rows in the foreign key tables would be.Row from being deleted when one or more child rows exist in other table(s). If a primary key table has referential integrity (foreign key) enforced, the REPLACE operation would fail because the MySQL prevents a parent.REPLACE wastes AUTO_INCREMENT primary key IDs as a new auto-increment ID is allocated when it inserts a matched row.Using REPLACE does have unexpected side effects or limitations. If unique key/row exists, INSERT IGNORE skips insertion so it effectively ignores the row in the insert statement. INSERT IGNORE is different to REPLACE.If the table does not have a primary key or unique key index, REPLACE becomes equivalent to INSERT, because there is no key/index to be checked toĭetermine whether the new row has a duplicate counterpart.The table must have a UNIQUE key or PRIMARY key constraint defined which MySQL can use to check if duplicate value exists.When using MySQL REPLACE function, consider the following guidelines. *Data for the table `email_sent_count` */ ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci `HashValue` char(32) COLLATE utf8_unicode_ci DEFAULT NULL, `SentCount` int(10) unsigned DEFAULT NULL, `Email` varchar(100) COLLATE utf8_unicode_ci DEFAULT NULL, `ID` int(10) unsigned NOT NULL AUTO_INCREMENT, *Table structure for table `email_sent_count` */ The table tracks how many times an email address has ![]() In this tutorial, we'll use a table called email_sent_count to demonstrate how REPLACE works. Not exist in the table in terms of a matching primary key or unique index, the new row is inserted. ![]() The new row after matching on a primary key or a unique index, the existing row is deleted, then the new row is inserted. It works like this: when an existing row in the table has the same value as MySQL REPLACE (INTO) function is a combined operation of DELETE + INSERT. Using MySQL REPLACE (INTO) to mimic DELETE + INSERT
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