/// <inheritdoc />
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
if (!Unique)
{
return(ValidationResult.Success);
}
if (value is null)
{
return(ValidationResult.Success);
}
if (validationContext.ObjectInstance is null)
{
return(ValidationResult.Success);
}
if (validationContext.TryGetDbContext(out var context))
{
var conn = context.Database.GetDbConnection();
ICustomCommand customCommand = null;
lock (Queries)
{
if (Queries.ContainsKey(validationContext.ObjectType))
{
customCommand = Queries[validationContext.ObjectType];
}
}
if (customCommand is null)
{
customCommand = validationContext.CreateFilteredCountQuery(true, validationContext.MemberName);
lock (Queries)
{
Queries[validationContext.ObjectType] = customCommand;
}
}
if (string.IsNullOrEmpty(customCommand.SqlStatement))
{
return(ValidationResult.Success);
}
if (conn.State == ConnectionState.Broken ||
conn.State == ConnectionState.Closed)
{
conn.Open();
}
var cmd = customCommand.CreateCommand(conn, validationContext.ObjectInstance);
var cnt = Convert.ToInt32(cmd.ExecuteScalar());
if (cnt > 0)
{
return(new ValidationResult("has already been used", new[] { validationContext.MemberName }));
}
}
return(ValidationResult.Success);
}
