How to Efficiently Duplicate Rows in MySQL with Many Columns?

Duplicating a Row in MySQL: Overcoming the Challenge of Multiple Columns

Problem:

Copying a row into the same table can be a challenge when dealing with a large number of columns. The traditional method involves explicitly listing all columns in the SELECT statement, but this becomes impractical with extensive tables.

Proposed Solution:

Using a temporary table as an intermediary can circumvent the issue of specifying each column. However, this involves creating a temporary table with identical columns and executing multiple statements for the duplication process.

Leonard Challis's Technique:

Leonard Challis offers an alternative approach that simplifies the process:

<br>CREATE TEMPORARY TABLE tmptable_1 SELECT * FROM table WHERE primarykey = 1;<br>UPDATE tmptable_1 SET primarykey = NULL;<br>INSERT INTO table SELECT * FROM tmptable_1;<br>DROP TEMPORARY TABLE IF EXISTS tmptable_1;<br>

Advantages:

• Utilizes a temporary table to avoid specifying columns manually.
• Sets the primary key to NULL for the temporary table, allowing MySQL to assign a unique value.
• Drops the temporary table after completion, preventing clutter.

Additional Considerations:

• To ensure only one row is inserted, consider adding LIMIT 1 to the INSERT INTO line.
• Append the primary key value to the temporary table name for easier identification.

Conclusion:

Leonard Challis's technique provides a straightforward and efficient solution for duplicating rows in tables with numerous columns. It avoids the need to manually list columns, reducing potential errors and simplifying the process.

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