将 Include 与参数化输入一起使用时，Entity Framework Core 抛出

Question

In EF Core 2.2.6 I need to construct a dynamic query with parameterized input. I start by constructing the statement:

var rawSql = new StringBuilder("SELECT * FROM dbo.Projects ");
var sqlParameters = new List<SqlParameter>();

rawSql.Append(string.Format("WHERE ProjectId < @param"));
sqlParameters.Add(new SqlParameter("@param", "20"));

Then I execute it:

var projects = await _context.Projects.FromSql(rawSql.ToString(), sqlParameters.ToArray())
    .ToListAsync();

This works. But if I add an Include it throws

ArgumentException: The SqlParameter is already contained by another SqlParameterCollection`

var projects = await _context.Projects.FromSql(rawSql.ToString(), sqlParameters.ToArray())
    .Include(p => p.Managers)
    .ToListAsync();

What am I doing wrong?

Answer 1

Try naming the parameter in a more concise way, perhaps the key "param" is already being used:

var rawSql = new StringBuilder("SELECT * FROM dbo.Projects ");
var sqlParameters = new List<SqlParameter>();

rawSql.Append(string.Format("WHERE ProjectId < @projectId"));
sqlParameters.Add(new SqlParameter("@projectId", "20"));