C#•3mo ago

SQL help

When trying to update a value in my database I get the error

No value given for one or more required parameters.

No value given for one or more required parameters.

however I heard this is common and usually means the SQL statement is wrong Here is my SQL string

C#
string _sSqlString = $"UPDATE Product SET SellPrice = {SellPrice} WHERE ProductName = {ProductName}";

databaseUtils.ExecuteSqlQuery(_sSqlString);

C#
string _sSqlString = $"UPDATE Product SET SellPrice = {SellPrice} WHERE ProductName = {ProductName}";

databaseUtils.ExecuteSqlQuery(_sSqlString);

After inputting the variables into the Sql it looks like this

C#
UPDATE Product SET SellPrice = 9 WHERE ProductName = apple

C#
UPDATE Product SET SellPrice = 9 WHERE ProductName = apple

A picture of the database is attached The ExecuteSqlQuery method works as intended, at least for all my other SQL requests, however they all use either DELETE, INSERT or SELECT Thanks

11 Replies

hutoanhill•3mo ago

i dont know what your problem is but i would be careful injecting stuff into a SQL statmetn the way you are. Its probubly a better idea to do

string _sSqlString = $"UPDATE Product SET SellPrice = @SellPrice WHERE ProductName = @ProductName";
// add this to a command

command.Paramiters.addWithValue("@ProductName", ProductName);
command.Paramiters.addWithValue("@SellPrice", SellPrice);

string _sSqlString = $"UPDATE Product SET SellPrice = @SellPrice WHERE ProductName = @ProductName";
// add this to a command

command.Paramiters.addWithValue("@ProductName", ProductName);
command.Paramiters.addWithValue("@SellPrice", SellPrice);

HazzzaOP•3mo ago

Yeah I was thinking about doing that but i didn't know how to properly implement it I will try and make it work and see if that may fix something as i saw on stack overflow that fixed it for someone else

hutoanhill•3mo ago

not a huge issue for testing, but if this becomes public facing it will open you up to SQL injection attacks

HazzzaOP•3mo ago

Its just for my computer science project for college

hutoanhill•3mo ago

your probubly fine than ¯\_(ツ)_/¯

HazzzaOP•3mo ago

yeaj yeah will get me more marks i guess

hutoanhill•3mo ago

depends on how much they care

HazzzaOP•3mo ago

i managed to fix it i needed ' ' around my variables 🤦‍♂️ thank you anyway for the help