Sql Exception occured.....Incorrect syntax near

Question

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My code are as follow: Even though I tried to handle the Sql Exception but still not working. I applied breakpoint and the Data Visualizer does not show the datatable......plz help

C#

conn.Open();
SqlDataAdapter da = new SqlDataAdapter("select * from tbl_reg where user_nm=''" + userInput + "", conn);
DataTable dt = new DataTable();
try
{
   da.Fill(dt);
   conn.Close();
   if (dt.Rows.Count == 0)
   {
      lbl_conf.Visible = true;
      lbl_conf.Text = "Sorry....No data found";
   }
   else
   {
      lbl_conf.Visible = true;
      lbl_conf.Text = "Keep going";
   }
}
catch(SqlException ex)
{
   if (ex is SqlException)
   {
      lbl_conf.Visible = true;
      lbl_conf.Text = "Handle the Sql Exception";
   }
   else
   {
      lbl_conf.Visible = true;
      lbl_conf.Text = "Unknown Exception occured";
   }
}

Posted 15-Nov-15 0:53am

Bit2 Developer

Updated 15-Nov-15 1:10am

Michael_Davies

v2

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OriginalGriff · Accepted Answer · 2015-11-15T01:12:00

In addition to what Krunal says, don't do it like that.
Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.

C#

SqlDataAdapter da = new SqlDataAdapter("select * from tbl_reg where user_nm=@UN", conn);
da.SelectCommand.Parameters.AddWithValue("@UN", userInput);

Michael_Davies · Accepted Answer · 2015-11-15T01:09:00

Solution 2

Hello,

You appear to have two single quotes before your variable and none after:

SqlDataAdapter da = new SqlDataAdapter("select * from tbl_reg where user_nm=''" + userInput + "", conn);

Try:

SqlDataAdapter da = new SqlDataAdapter("select * from tbl_reg where user_nm='" + userInput + "'", conn);

Or better still use a parameterised query.

Posted 15-Nov-15 1:09am

Michael_Davies

Comments

Bit2 Developer 20-Nov-15 6:07am

Thanks Michael

Krunal Rohit · Accepted Answer · 2015-11-15T01:07:00

Solution 1

"select * from tbl_reg where user_nm="'"+ userInput + "'"
try with this query.
Or better use a parameterised query.

SqlDataAdapter da = new SqlDataAdapter("select * from tbl_reg where user_nm=@user_name", conn);<br />
da.SelectCommand.Parameters.AddWithValue("@user_name", username);

-KR

Posted 15-Nov-15 1:07am

Krunal Rohit

Updated 15-Nov-15 2:07am

v2

Comments

Bit2 Developer 20-Nov-15 6:08am

Thanks Rohit.
If possible could u plz give me a brief note on parameterised query as u mentioned above.

Krunal Rohit 20-Nov-15 6:13am

Glad I could help. Please refer this-
Using-Parameterized-queries-to-prevent-SQL-Injection-Attacks-in-SQL-Server[^]

-KR

Bit2 Developer 20-Nov-15 7:53am

Wow....awesome.
Thanks again.