Why Does My C# Code Always Return 0 for the Inserted Row ID?

Retrieve Inserted Row ID Effectively in C#

When working with database operations, capturing the unique identifier of an inserted row is crucial. This is especially true when crafting the next segment of your code. However, encountering a consistent return value of 0 despite the actual ID having a non-zero value can be frustrating.

Let's delve into the issue you're facing. The provided C# code attempts to retrieve the ID of an inserted row, but it always returns 0. This behavior stems from an oversight in the code's execution.

The crux of the problem lies within the following line:

int id = Convert.ToInt32(comm.ExecuteScalar());

While the ExecuteScalar method is capable of retrieving a single value from the executed query, it's crucial to note that it does not automatically return the ID of the inserted row. The issue arises when you attempt to cast the returned value to an int using Convert.ToInt32. This casting can lead to incorrect conversions, resulting in the returned 0.

To rectify this situation, we need to replace ExecuteScalar with ExecuteNonQuery. This function is responsible for executing a non-query statement, such as an insert operation. Following the successful execution of the insert statement, you can leverage the LastInsertedId property of the MySqlCommand object to retrieve the ID of the newly created row:

MySqlCommand comm = connect.CreateCommand();
comm.CommandText = insertStatement;
comm.ExecuteNonQuery();
long id = comm.LastInsertedId;

By implementing this adjustment, you can effectively obtain the ID of the inserted row, ensuring a seamless transition to the next phase of your code's execution.

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