Container and unbounded string fields are not allowed in a WHERE expression.

I had a requirement to store huge data of xml into AX table i.e. I used string size as [MEMO].
Response1, Response2 & Response3 are Memo Fields.

Now my requirement is to perform to select some data based on where conditions checking Response 1, Response 2 &; Response 3 parameters but it gives me Error

  while select * from appLog
            where appLog.ReceiptNo == ""  && appLog.Response1 != "" && appLog.Response2 != "" && appLog.Response3 == ""
        {
                resultSet.addEnd(appLog.Response2);
       
        }


Container and unbounded string fields are not allowed in a WHERE expression.

Note: After finding error details I came to know you can not use MEMO fields in where clause and have to use IF condition .

Therefore the query was changed as below.

  while select * from appLog
            where appLog.ReceiptNo == ""
        {
            response1 = appLog.Response1;
            response2 = appLog.Response2;
            response3 = appLog.Response3;
         
            if(response1 != "" && response2 != "" && response3 == "")
            {
                resultSet.addEnd(appLog.Response2);
            }
        }

Executing SQL Query in Dynamics AX

X++ language supports a number of ways to execute native SQL against any SQL data source.

Note: don't forget to set RunOn Property to Server of the class. Job:

static void BillingQuery(Args _args)
{
    RunSqlQuery q = new RunSqlQuery();
    q.RunSqlQueryMethod();

}

Class:

class RunSqlQuery
{
}

public void RunSqlQueryMethod()
{
     str sql;
    Connection conn;
    SqlStatementExecutePermission permission;
    Statement Stmt;
    ResultSet R;
    str result;
    ;
    sql = "select ACCOUNTNUM from custTable";

    conn = new Connection();
    permission = new SqlStatementExecutePermission(sql);
    permission.assert();

    Stmt = conn.createStatement();
    R = Stmt.executeQuery(sql);
    while ( R.next() )
    {
        result =  R.getString(1);
    }

    // the permissions needs to be reverted back to original condition.
    CodeAccessPermission::revertAssert();
}

Below the useful links.

http://blog.rahulsharma.in/2010/04/dynamics-ax-sqlstatementexecutepermissi.html

https://msdax.wordpress.com/2010/06/21/executing-sql-directly-from-x/