Type conversion in SQL Server (syntax error occurred when converting varchar value to a column whose data type is int)

The error is described as follows:

(1) menu_id is an int-type field in the uds_menu table.

(2) countycode is a field of the varchar type in the sys_userinf table.

The following error occurs during conversion:

Syntax error when converting varchar value to a column whose data type is intSolution:

Use the cast () function to convert the menu_id to the character type.Cast (menu_id as varchar (50 ))And then the matching and comparison will not cause errors.

Strsql = "select menu_id, [menu_name] from [uds_menu] Where cast (menu_id as varchar (50) = (select countycode as menu_id from sys_userinf where [ID] =" + Int. parse (ID) + ")";