我正在尝试使用 C# 更改表添加列

Question

I would like to add column to the SQL table programmatically using C#.

This is my code.

SqlConnection con = new SqlConnection(conString);
con.Open();
string str = "ALTER TABLE  [dbo].[tblQuiz] ADD '" + txtQuizNo.Text.ToString() +"' Varchar(50) NULL ";
SqlCommand com = new SqlCommand(str, con);
com.ExecuteNonQuery();
con.Close();

When I execute the program it say's:

Incorrect syntax near the column name.

Is it possible to add column to the SQL database programmatically?

Answer 1

Is it possible to add column to the sql database programmatically?

SQL Server processes SQL Commands. IT DOES NOT CARE WHERE THEY COME FROM.

Also note that your error message CLEARLY seems to state this:

it say's that Incorrect syntax n

Incorrect Syntax means EXACTLY THIS.

ALTER TABLE [dbo].[tblQuiz] ADD '" + txtQuizNo.Text.ToString() +"'

Why do you even consider:

• using this REALLY outdated syntax to add to strings.
• Turning the name of the new field into a STRING CONSTANT (by bracketing it in ') instead of a name constant? Names are not strings in SQL - in fact it is illegal to use constants or variables instead of names. So, you create what it says - a SYNTAX error - by making the name a string constant.

Here is a simple beginner debug hint: Next time a SQL command fails like that, log it or use a debugger to get the FINISHED string. Copy/paste it into SSMS and see whether it runs there. Your whole question would be moot if you tried - because you would CLEARLY see it is NOT related to C# because you get the same error in SSMS.