How to insert an SQL literal as a query parameter in Dapper?

Question

I want to insert part of SQL statement as a parameter instead of concatenation to have it neat:

connection.Query(@"
    SELECT @Fields
    FROM Table
    WHERE ID = @Id
    ", new { Fields = "A, B", Id = 1});

I tried wrapping the parameter string in a custom class and mapping the class using Dapper

public class SqlString
{
    public readonly string Value;

    public SqlString(string sql)
    {
        Value = sql;
    }

    public override string ToString()
    {
        return Value;
    }
}

...

Dapper.SqlMapper.AddTypeMap(typeof(SqlString), System.Data.DbType.Object);

but to no avail.

Cam Bruce · Accepted Answer · 2014-04-16 23:02:14Z

2

You can't parameterize field names in T-SQL.

You will have to generate the dynamic SQL with your dynamic field names before you pass the sql string into the Connection.Query() method.

answered Apr 16, 2014 at 23:02

Cam Bruce

5,68924 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Herman Kan Over a year ago

Thank you. Yes, I had to resort to my own SQL injector.

Collectives™ on Stack Overflow

How to insert an SQL literal as a query parameter in Dapper?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related