If the count is 1 for single-row REPLACE, a row was inserted and no rows were deleted. Rows Affected = Sum of the rows deleted and inserted. The REPLACE statement returns a count to indicate the number of rows affected. | ID | Name | Countr圜ode | District | Population | Mysql> SELECT * FROM City WHERE Name=’New York’ We will change the value of the Population for the New York City to 8009000 using the REPLACE statement. The primary key for the Country table is ID.įor example, the current row that we replace in the table is shown below. It becomes equivalent to INSERT, because there is no index to be used to determine whether a new row is duplicate to another existing row. Note that unless the table has a PRIMARY KEY or a UNIQUE constraint, using a REPLACE statement makes no sense. ![]() | ID | int | NO | PRI | NULL | auto_increment | | Field | Type | Null | Key | Default | Extra | In this example, we will replace a current row of data in the Country table from the world MySQL database. We cannot refer to values from the current row and use them in the new row. Any missing columns are set to their default values, just like in the INSERT statement. The values for all the columns are taken from the values specified in the REPLACE statement. Mysql> REPLACE INTO table_name (column_list) VALUES(values_list) The REPLACE statement uses the following syntax: ![]() ![]() The INSERT statement fails because a duplicate-key error occurs for a primary key or unique constraint if the column has the same value for new row and existing old row. REPLACE works like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or UNIQUE constraint, the old row is deleted before the new row is inserted. The statement either inserts or deletes and inserts rows. The REPLACE statement is a MySQL extension to the SQL standard. In this tutorial, we will learn about MySQL REPLACE statement.
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