Why is my SQL INSERT statement with parameters failing, and how can I fix it?

SqlParameter Parameters - Insert using Parameters

Question:

When attempting to insert a record into a database using an SQL command, the code execution fails. The provided code includes:

SqlCommand comand = new SqlCommand("INSERT INTO Product_table Values(@Product_Name,@Product_Price,@Product_Profit,@p)", connect);
SqlParameter ppar = new SqlParameter();
ppar.ParameterName = "@Product_Name";
ppar.Value = textBox1.Text;
MessageBox.Show("Done");
comaand.Parameters.Add(ppar);

Answer:

To successfully insert a record using parameters, the following code should be used:

SqlCommand cmd = new SqlCommand("INSERT INTO Product_table Values(@Product_Name, @Product_Price, @Product_Profit, @p)", connect);
cmd.Parameters.Add("@Product_Name", SqlDbType.NVarChar, ProductNameSizeHere).Value = txtProductName.Text;
cmd.Parameters.Add("@Product_Price", SqlDbType.Int).Value = txtProductPrice.Text;
cmd.Parameters.Add("@Product_Profit", SqlDbType.Int).Value = txtProductProfit.Text;
cmd.Parameters.Add("@p", SqlDbType.NVarChar, PSizeHere).Value = txtP.Text;
cmd.ExecuteNonQuery();

Explanation:

• Avoid using AddWithValue, as it can cause data type conversion issues.
• Specify the column names in the INSERT statement (e.g., @Product_Name, @Product_Price) and provide their corresponding values using cmd.Parameters.Add(...).
• Specify the data type of each parameter using SqlDbType.
• Use cmd.ExecuteNonQuery() to execute the command and insert the record into the database.

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