Скачать или смотреть Solving the Incorrect Syntax near '(' Error in SQL Server Queries

Learn how to troubleshoot and resolve the `Incorrect Syntax near '('` error in SQL Server when dynamically creating tables from ASP.NET forms.
---
This video is based on the question https://stackoverflow.com/q/63107330/ asked by the user 'Turkia Golli' ( https://stackoverflow.com/u/11950612/ ) and on the answer https://stackoverflow.com/a/63107575/ provided by the user 'ELinda' ( https://stackoverflow.com/u/7484259/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Incorrect Syntax near '(' SQL Server Query

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Troubleshooting the SQL Server Error: Incorrect Syntax near '('

As a developer, few things can be as frustrating as encountering an error that halts your progress. One such common error when working with SQL Server and C# is the Incorrect Syntax near '('. This error can arise when attempting to create tables dynamically based on input from an ASP.NET form. In this guide, we'll break down this problem and explore how to resolve it effectively.

Understanding the Context: The Error

When we send a SQL command to create a table, we expect it to execute without any issues. However, if you see the following error in your debug output:

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

it typically indicates that there is a problem with the SQL command syntax specifically involving parentheses. This can occur in various situations, particularly when you are dynamically forming SQL queries using variables.

The Problematic Code Snippet

Let's take a closer look at the section of code that is likely causing this error:

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

colName: This variable holds the name of the column.

datatype: This represents the SQL data type for the column which can vary between types.

maxChar: A variable representing the maximum number of characters for certain data types.

Analyzing the Data Types

Here lies the core of the issue—if your data type does not accept a length parameter, such as int or date, appending parentheses and a number (i.e., maxChar) to them will result in SQL syntax errors. Consider the following examples:

Working: varchar(50) or char(10) - These types require a length parameter.

Not Working: int() or date() - These do not require a length and will lead to a syntax error if the parentheses are included.

Solution: Conditional Parentheses

To resolve the error, you will need to conditionally build the SQL string based on whether or not the data type requires a maxChar parameter. Here’s how to do it:

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

Implementing the Solution

Step 1: Identify All Data Types

First, compile a complete list of data types that your application might encounter. Ensure you handle cases for types that do and do not require parentheses.

Step 2: Modify the SQL String Formation

Incorporate the conditional logic into your existing SQL string formation code as shown above. This ensures that parentheses are only added for relevant data types.

Step 3: Testing the Implementation

After you've made these changes, conduct thorough testing with different data types, especially the ones that previously caused the syntax errors. Ensure that your application does not produce any more SQL errors.

Conclusion: Overcoming SQL Syntax Errors

SQL syntax errors can be daunting, but by carefully analyzing your code and understanding the underlying causes, you can effectively troubleshoot these issues. Implementing conditional logic when forming SQL queries not only fixes the immediate problem but also protects your application against similar errors in the future.

If you have more questions or need further guidance, feel free to reach out. Happy coding!