更新 SQL 中的主键值

Question

I am creating a form that updates the SQL database with content written in it. ClientCode is a primary key. My update query is the following:

string query = $@"UPDATE {clientTableName}
                                SET ClientCode = @clientCode,
                                    CompanyName = @companyName,
                                    Address1 = @address1,
                                    Address2 = @address2,
                                    City = @city,
                                    Province = @province,
                                    PostalCode = @postalCode,
                                    YTDSales = @ytdSales,
                                    CreditHold = @creditHold,
                                    Notes = @notes
                                WHERE ClientCode = @clientCode";

Problem with this query is it will select the new clientCode in the where cause, meaning that the query will not be able to select the correct primary key.

For example, if I type "BOTTN", the query will look for "BOTTN" instead of "BOTTM" in the where cause.

How I can solve this?

Answer 1

You need to differentiate between the old clientCode and the new clientCode. The WHERE clause needs to contain the old clientCode in order to target the existing row in the database. Then you can update the row, including the value for the new clientCode.

string query = $@"UPDATE {clientTableName}
                            SET ClientCode = @newClientCode,     -- NEW
                                CompanyName = @companyName,
                                Address1 = @address1,
                                Address2 = @address2,
                                City = @city,
                                Province = @province,
                                PostalCode = @postalCode,
                                YTDSales = @ytdSales,
                                CreditHold = @creditHold,
                                Notes = @notes
                            WHERE ClientCode = @oldClientCode";  -- OLD

Get the new client code from the text box in your EditDialog and save the old client code as a member variable or something when you retrieve the row from the database in order to display the individual fields in the EditDialog .