delete data from sql database table

Question

1.00/5 (2 votes)

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SqlConnection con = new SqlConnection();
                con.ConnectionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=d:\users\vivek\documents\visual studio 2010\Projects\soft\soft\database\vks.mdf;Integrated Security=True;User Instance=True";
                string str;
                str = "insert into qualification_master (qualification_name) values('" + comboBox1.Text + "')";
                con.Open();
                SqlCommand cmd = new SqlCommand(str, con);
                cmd.ExecuteNonQuery();

what change in above code for delete data ?

Posted 4-Aug-11 0:01am

vivek shaushi

Updated 4-Aug-11 0:02am

Toniyo Jackson

v2

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3 solutions

Solution 1

First, format your code using code blocks.
Second, use parameterized queries, your code is susceptible to SQL Injection attacks.

Here is the answer.

SQL

DELETE FROM qualification_master WHERE qualification_name = @yourValue

Posted 4-Aug-11 0:04am

Shameel

Solution 3

DELETE FROM qualification_master

Trust me this will delete all the data from table. Don't use

Where

clause and never use parametrized query in .Net.

Please guys don't post answer to these type questions.
This guy even don't know the SQL command, how can we help this guy?

He want help on SQL (subject: delete data) has a tag of C#.

Posted 4-Aug-11 0:10am

Suresh Suthar

Comments

vivek shaushi 4-Aug-11 6:12am

tari ma no bhosdo

Toniyo Jackson 4-Aug-11 6:15am

What are you talking man? If you don't know something only you will come here. Just help him in a right way. See my answer. I given him the answer and given some links to learn sql also. We have to help new guys.

Suresh Suthar 4-Aug-11 6:21am

Just see the comment by the guy you helped.

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Toniyo Jackson · Accepted Answer · 2011-08-04T00:04:00

Solution 2

Looks like you have no idea about sql queries.

str = "DELETE FROM qualification_master WHERE qualification_name = '" + comboBox1.Text + "'";

If you have primary key in table, you have to use that in where condition.

Check this for delete query.

http://www.w3schools.com/sql/sql_delete.asp[^]

To learn sql start from here[^].

Posted 4-Aug-11 0:04am

Toniyo Jackson

Updated 4-Aug-11 0:06am

v2

Comments

UJimbo 4-Aug-11 6:06am

pretty much

vivek shaushi 4-Aug-11 6:07am

but which method i can use cmd.executenonquery or other????

Toniyo Jackson 4-Aug-11 6:09am

cmd.executenonquery

koolprasad2003 4-Aug-11 6:10am

Use ExecuteNonQuery() method which will return you Integer value.

vivek shaushi 4-Aug-11 6:10am

thanx bro

Toniyo Jackson 4-Aug-11 6:10am

You are welcome :)