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am going to insert value into table but am facing an issue and am wonder like why this error occurred.

My query like this.

string str = "insert into Tblcustomer values ('" + txtname.Text + "','" + txtaddress.Text + "','" + txtmobile.Text + "','" + txtemail.Text + "','" + InDate.Text + "','" + OutDate.Text + "','" + combostate.Text + "','" + txtperson.Text + "','" + txtRoomType.Text + "','"+comboRoomNo.Text+"','"+txtblock.Text+"')";


What I have tried:

My query like this.

<pre>string str = "insert into Tblcustomer values ('" + txtname.Text + "','" + txtaddress.Text + "','" + txtmobile.Text + "','" + txtemail.Text + "','" + InDate.Text + "','" + OutDate.Text + "','" + combostate.Text + "','" + txtperson.Text + "','" + txtRoomType.Text + "','"+comboRoomNo.Text+"','"+txtblock.Text+"')";
Posted
Updated 19-May-20 20:00pm

INSERT ... VALUES without column names is positional. If the first column is an IDENTITY column (probably), you're trying to put a "name" into it. The message is self-explanatory after that.
 
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Member 11297177 24-May-20 10:14am    
yes it was working fine , thanks for solution
To add to what Gerry says, always list the column names you want to insert into - that way your code still works if the DB columns are reorganised later:
SQL
INSERT INTO MyTable (ColumnName1, CoulumnName2) VALUES (...


But ... Don't do it like that! Never 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. Always use Parameterized queries instead.

When you concatenate strings, you cause problems because SQL receives commands like:
SQL
SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'
The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:
SQL
SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'
Which SQL sees as three separate commands:
SQL
SELECT * FROM MyTable WHERE StreetAddress = 'x';
A perfectly valid SELECT
SQL
DROP TABLE MyTable;
A perfectly valid "delete the table" command
SQL
--'
And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.

So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?
 
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