How to Avoid inserting duplicate values

Question

Sir I have win form containing four fields first field auto generate number dispalyed remaining user input values my question is if i select check box auto generate number will disable then able to give input number please help me

ketan borsdiya · Answer

Hi Yesubabu If your check box is checked then call one query for exists that number. If number is exists then show message please add unique number. if you want to allow insert duplicate value then use SET IDENTITY_INSERT orders ON --Write your insert query here SET IDENTITY_INSERT orders OFF

Vinay Singh · Answer

Disable identity column of your sql table. SET IDENTITY_INSERT orders ON will turn ON the ability to insert specific values (that you specify) into a table with an IDENTITY column. SET IDENTITY_INSERT orders OFF https://msdn.microsoft.com/en-IN/library/ms188059.aspx http://stackoverflow.com/questions/1234780/turn-off-identity-insert-for-dataset-insert http://stackoverflow.com/questions/7063501/how-to-turn-identity-insert-on-and-off-using-sql-server-2008