VB.net Tutorial save data in SQL server using VB.net and Prevent duplicate data entry

[@snaveenkumar5812]

there @code, @name and is where it means

[@piotrsikorski7956]

@code, @fname, @lname, and @marks are parameters used in an SQL command. The SQL command is trying to insert values into a table named "Table4". In 2022 version it should be in []. It checks if a row exists in the table where the value in the code_student column matches the value of the @code parameter. If there is no such row, the command inserts a new row with values for the code_student, firstname, lastname, and marks columns. The values for these columns are provided through parameters: @code, @fname, @lname, and @marks. These parameters are placeholders in the SQL command that will be replaced with actual values when the command is executed. In the VBA code, these parameters are set using the SqlCommand object's Parameters property. The actual values to be inserted into the table can be set by assigning values to these parameters before executing the command.