Solving System.Data.SqlClient.SqlException: How to Fix Incorrect Parameter Syntax in SQL Execution

Описание: Discover how to resolve 'System.Data.SqlClient.SqlException' errors caused by incorrect parameter syntax when executing SQL commands in C# .
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Solving System.Data.SqlClient.SqlException: How to Fix Incorrect Parameter Syntax in SQL Execution

When working with databases in C# , encountering exceptions can be quite frustrating. One common error developers face is the System.Data.SqlClient.SqlException, specifically when it relates to improper syntax in SQL commands. The message, “Incorrect syntax near @ UserPic”, indicates there is an issue with how parameters are defined in the SQL command. In this guide, we will discuss the cause of this error and how to successfully resolve it.

Understanding the Problem

In the provided C# code, the method UpdateUser is designed to execute a stored procedure (dbo.updateUser) to update a user’s information in the database. The method uses Dapper, a simple object mapper for .NET that helps execute SQL queries.

Observing the Error

The error occurs during the execution of the UpdateUser method, specifically at the point where it attempts to run the SQL command. The error message points out the incorrect syntax near the @ UserPic parameter, which suggests that parameters are not correctly separated in the SQL command string.

Solution to the Problem

To rectify the syntax error in the SQL command, it's essential to ensure that all parameters are properly indicated and separated by commas when executing stored procedures. Let’s break down the solution into a few clear steps:

1. Modify the SQL Execution Command

The error can be resolved by adding commas between the input parameters within the SQL command. Here’s the corrected implementation:

[[See Video to Reveal this Text or Code Snippet]]

Key Changes:

Ensure that all parameters in the EXEC statement are separated by commas. The corrected line reads @ UserId = @ UserId, @ UserPic = @ UserPic, @ Name = @ Name, @ Password = @ Password.

2. Test the Update Functionality

After making the necessary changes, it is essential to test the ChangeUser method (which calls UpdateUser) to ensure that it works correctly. Using a JSON payload similar to the following will help verify the entire functionality:

[[See Video to Reveal this Text or Code Snippet]]

Example of the Full ChangeUser Method

Here’s how the complete method now looks after adjustments:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Fixing the System.Data.SqlClient.SqlException associated with incorrect parameter syntax is straightforward once you understand the cause. By ensuring that each parameter is properly separated within the SQL execution string, you can prevent these frustrating errors and maintain seamless interactions with your database.

Implement the solutions provided, and let the application run smoothly without encountering syntax issues again!

Remember, clear communication with the database is key to a well-functioning application!