CODEWITHSUNDEEP
c#mysqlwpfparameters
Mr Rubix
Mr Rubix

Reputation: 1519

c# MySqlCommand.Parameters.AddWithValue, parameters to express a table, resulted command have a single quote added

my problem is that two undesired single quote appear in my command when i use AddWithValue. This is how i call my function:

string sqlTableName = "the_table_i_want";
DataTable myDataTable = SQLcom.SelectLastValueInTab(sqlTableName);

My Function;

public static DataTable SelectLastValueInTab(string TableName)
    {
        using (MySqlConnection con = new MySqlConnection(ConnStr))
        {
            using (MySqlCommand myCommand = new MySqlCommand("SELECT * FROM @TabName ORDER BY id DESC LIMIT 1", con))
            {
                myCommand.Parameters.AddWithValue("@TabName", TableName);
                try
                {
                    con.Open();
                    MySqlDataReader testreader = myCommand.ExecuteReader();

The Resulted command is :

"SELECT * FROM 'the_table_i_want' ORDER BY id DESC LIMIT 1"

And is suppose to be :

"SELECT * FROM the_table_i_want ORDER BY id DESC LIMIT 1"

It cause the program to crash beacause i have:

a syntax error near ''the_table_i_want' ORDER BY id DESC LIMIT 1'

PS : if i don't use AddWithValuechange and change

@TabName for the_table_i_want

in the MySqlCommand it works perfectly !

Thanks a lot !

Daniel G.B

Upvotes: 0

Views: 891

Answers (1)

Nagaraj Raveendran
Nagaraj Raveendran

Reputation: 1220

As the comments suggest, You cannot use parameters to express a table or field name. Alternative approach would be appending the table name to the query.

public static DataTable SelectLastValueInTab(string TableName)
{
    using (MySqlConnection con = new MySqlConnection(ConnStr))
    {
        string qry = "SELECT * FROM " + TableName + " ORDER BY id DESC LIMIT 1";
        using (MySqlCommand myCommand = new MySqlCommand(qry, con))
        {
            try
            {
                con.Open();
                MySqlDataReader testreader = myCommand.ExecuteReader();

Upvotes: 1

Related Questions