I have built a common app that works with PostgreSQL and should work on Oracle.
However i'm getting strange errors when inserting records through a parametrized query.
My formatted query looks like this:
"INSERT INTO layer_mapping VALUES (#lm_id,#lm_layer_name,#lm_layer_file);"
Unlike Npgsql which documents how to use the parameters, i could not found how Oracle "prefers" them to be used. I could only find :1, :2, :3, for example.
I do not wanto use sequential parameters, i want to use them in a named way.
Is there a way to do it? Am i doing something wrong?
Thanks
You can use named parameters with ODP.NET like so:
using (var cx=new OracleConnection(connString)){
using(var cmd=cx.CreateCommand()){
cmd.CommandText="Select * from foo_table where bar=:bar";
cmd.BindByName=true;
cmd.Parameters.Add("bar",barValue);
///...
}
}
I made this lib https://github.com/pedro-muniz/ODPNetConnect/blob/master/ODPNetConnect.cs
so you can do parameterized write and read like this:
ODPNetConnect odp = new ODPNetConnect();
if (!String.IsNullOrWhiteSpace(odp.ERROR))
{
throw new Exception(odp.ERROR);
}
//Write:
string sql = #"INSERT INTO TABLE (D1, D2, D3) VALUES (:D1, :D2, :D3)";
Dictionary<string, object> params = new Dictionary<string, object>();
params["D1"] = "D1";
params["D2"] = "D2";
params["D3"] = "D3";
int affectedRows = odp.ParameterizedWrite(sql, params);
if (!String.IsNullOrWhiteSpace(odp.ERROR))
{
throw new Exception(odp.ERROR);
}
//read
string sql = #"SELECT * FROM TABLE WHERE D1 = :D1";
Dictionary<string, object> params = new Dictionary<string, object>();
params["D1"] = "D1";
DataTable dt = odp.ParameterizedRead(sql, params);
if (!String.IsNullOrWhiteSpace(odp.ERROR))
{
throw new Exception(odp.ERROR);
}
Notes: you have to change these lines in ODPNetConnect.cs to set connection string:
static private string devConnectionString = "SET YOUR DEV CONNECTION STRING";
static private string productionConnectionString = "SET YOUR PRODUCTION CONNECTION STRING";
And you need to change line 123 to set environment to dev or prod.
public OracleConnection GetConnection(string env = "dev", bool cacheOn = false)
Related
NamedParameterJdbcTemplate namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(jdbcTemplate.getDataSource());
MapSqlParameterSource params = new MapSqlParameterSource();
params.addValue("STR_REF",(String)strRefkeys);
String sql = "SELECT TAGDESCRIPTION FROM xx, xx WHERE localeid='en_US' AND " +
"xx.TAGID=xx.RECORDID and TAGDESCRIPTION is not null AND xx.REFERENCEKEY in (:STR_REF)";
List<String> ifCurrent = namedParameterJdbcTemplate.queryForList(sql, params,String.class);
not getting any results in ifCurrent although run same query as SQL query and get results.
Am I passing any wrong params?
This is what is getting passed in strRefkeys
for(String refStr : strRefkeysLst) {
strRefkeysBuf.append("'");
strRefkeysBuf.append(refStr.toUpperCase());
strRefkeysBuf.append("',");
}
strRefkeys = strRefkeysBuf.toString();
if(strRefkeys.trim().length()>1){strRefkeys = strRefkeys.substring(0, strRefkeys.length()-1);}
You're passing a string parameter where a collection of values is expected. strRefKeys should be a set of accepted values for the REFERENCEKEY column.
Why do I get the error Must declare the scalar variable "#ChargeRate"?
public static void InsertSqlSerwer2(BatteryFullInfo info)
{
SqlConnection MSDEconn;
MSDEconn = new SqlConnection();
MSDEconn.ConnectionString = #"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\HOME\Documents\NewDataBase.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";
MSDEconn.Open();
string komenda = "INSERT into Battery_Information VALUES (#ChargeRate, #Id, #DischargeRate, #RemainingCapacity, #Voltage, #BatteryLifePercent, #ChargeStatus)";
SqlCommand MSDEcommand = new SqlCommand(komenda, MSDEconn);
MSDEcommand.Parameters.AddWithValue("#ChargeRate", info.ChargeRate);
MSDEcommand.Parameters.AddWithValue("#Id", info.IdBateria);
MSDEcommand.Parameters.AddWithValue("#DischargeRate", info.DischargeRate);
MSDEcommand.Parameters.AddWithValue("#RemainingCapacity", info.RemainingCapacity);
MSDEcommand.Parameters.AddWithValue("#Voltage", info.Voltage);
MSDEcommand.Parameters.AddWithValue("#BatteryLifePercent", info.BatteryLifePercent);
MSDEcommand.Parameters.AddWithValue("#ChargeStatus", info.ChargeStatus);
MSDEcommand.Parameters.Clear();
MSDEcommand.ExecuteNonQuery();
MSDEconn.Close();
}
Because you are clearing your parameters. You go through all of the effort to AddWithValue, and then you execute MSDEcommand.Parameters.Clear(), which gets rid of them all. Remove that line and I think this will work.
Note: I'm specifically not using Fluent NHibernate but am using 3.x's built-in mapping style. However, I am getting a blank recordset when I think I should be getting records returned.
I'm sure I'm doing something wrong and it's driving me up a wall. :)
Background / Setup
I have an Oracle 11g database for a product by IBM called Maximo
This product has a table called workorder which lists workorders; that table has a field called "wonum" which represents a unique work order number.
I have a "reporting" user which can access the table via the maximo schema
e.g. "select * from maximo.workorder"
I am using Oracle's Managed ODP.NET DLL to accomplish data tasks, and using it for the first time.
Things I've Tried
I created a basic console application to test this
I added the OracleManagedClientDriver.cs from the NHibernate.Driver on the master branch (it is not officially in the release I'm using).
I created a POCO called WorkorderBriefBrief, which only has a WorkorderNumber field.
I created a class map, WorkorderBriefBriefMap, which maps only that value as a read-only value.
I created a console application with console output to attempt to write the lines of work orders.
The session and transaction appear to open correct,
I tested a standard ODP.NET OracleConnection to my connection string
The Code
POCO: WorkorderBriefBrief.cs
namespace PEApps.Model.WorkorderQuery
{
public class WorkorderBriefBrief
{
public virtual string WorkorderNumber { get; set; }
}
}
Mapping: WorkorderBriefBriefMap.cs
using NHibernate.Mapping.ByCode;
using NHibernate.Mapping.ByCode.Conformist;
using PEApps.Model.WorkorderQuery;
namespace ConsoleTests
{
public class WorkorderBriefBriefMap : ClassMapping<WorkorderBriefBrief>
{
public WorkorderBriefBriefMap()
{
Schema("MAXIMO");
Table("WORKORDER");
Property(x=>x.WorkorderNumber, m =>
{
m.Access(Accessor.ReadOnly);
m.Column("WONUM");
});
}
}
}
Putting it Together: Program.cs
namespace ConsoleTests
{
class Program
{
static void Main(string[] args)
{
NHibernateProfiler.Initialize();
try
{
var cfg = new Configuration();
cfg
.DataBaseIntegration(db =>
{
db.ConnectionString = "[Redacted]";
db.Dialect<Oracle10gDialect>();
db.Driver<OracleManagedDataClientDriver>();
db.KeywordsAutoImport = Hbm2DDLKeyWords.AutoQuote;
db.BatchSize = 500;
db.LogSqlInConsole = true;
})
.AddAssembly(typeof(WorkorderBriefBriefMap).Assembly)
.SessionFactory().GenerateStatistics();
var factory = cfg.BuildSessionFactory();
List<WorkorderBriefBrief> query;
using (var session = factory.OpenSession())
{
Console.WriteLine("session opened");
Console.ReadLine();
using (var transaction = session.BeginTransaction())
{
Console.WriteLine("transaction opened");
Console.ReadLine();
query =
(from workorderbriefbrief in session.Query<WorkorderBriefBrief>() select workorderbriefbrief)
.ToList();
transaction.Commit();
Console.WriteLine("Transaction Committed");
}
}
Console.WriteLine("result length is {0}", query.Count);
Console.WriteLine("about to write WOs");
foreach (WorkorderBriefBrief wo in query)
{
Console.WriteLine("{0}", wo.WorkorderNumber);
}
Console.WriteLine("DONE!");
Console.ReadLine();
// Test a standard connection below
string constr = "[Redacted]";
OracleConnection con = new OracleConnection(constr);
con.Open();
Console.WriteLine("Connected to Oracle Database {0}, {1}", con.ServerVersion, con.DatabaseName.ToString());
con.Dispose();
Console.WriteLine("Press RETURN to exit.");
Console.ReadLine();
}
catch (Exception ex)
{
Console.WriteLine("Error : {0}", ex);
Console.ReadLine();
}
}
}
}
Thanks in advance for any help you can give!
Update
The following code (standard ADO.NET with OracleDataReader) works fine, returning the 16 workorder numbers that it should. To me, this points to my use of NHibernate more than the Oracle Managed ODP.NET. So I'm hoping it's just something stupid that I did above in the mapping or configuration.
// Test a standard connection below
string constr = "[Redacted]";
OracleConnection con = new Oracle.ManagedDataAccess.Client.OracleConnection(constr);
con.Open();
Console.WriteLine("Connected to Oracle Database {0}, {1}", con.ServerVersion, con.DatabaseName);
var cmd = new OracleCommand();
cmd.Connection = con;
cmd.CommandText = "select wonum from maximo.workorder where upper(reportedby) = 'MAXADMIN'";
cmd.CommandType = CommandType.Text;
Oracle.ManagedDataAccess.Client.OracleDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader.GetString(0));
}
con.Dispose();
When configuring NHibernate, you need to tell it about your mappings.
I found the answer -- thanks to Oskar's initial suggestion, I realized it wasn't just that I hadn't added the assembly, I also needed to create a new mapper.
to do this, I added the following code to the configuration before building my session factory:
var mapper = new ModelMapper();
//define mappingType(s) -- could be an array; in my case it was just 1
var mappingType = typeof (WorkorderBriefBriefMap);
//use AddMappings instead if you're mapping an array
mapper.AddMapping(mappingType);
//add the compiled results of the mapper to the configuration
cfg.AddMapping(mapper.CompileMappingForAllExplicitlyAddedEntities());
var factory = cfg.BuildSessionFactory();
I was wondering if we can convert a Linq Query on the Entity Framework and save the query to the database by converting it to an Expression Tree and Serializing. Can someone please help me on this and point me in a right direction whether this can be done or not. Any help is greatly appreciated on this.
Thanks,
Ajay.
i released a library for that purpose just yesterday. Serialize.Linq. It serializes linq expressions to xml, json or binary.
using System.Linq.Expressions
using Serialize.Linq.Extensions;
Expression<Func<Person, bool>> query = p => p.LastName == "Miller"
&& p.FirstName.StartsWith("M");
Console.WriteLine(query.ToJson());
Console.WriteLine(query.ToXml());
You could turn the query into a string and then save the string.
This is from an answer by Nick Berardi:
var result = from x in appEntities
where x.id = 32
select x;
var sql = ((System.Data.Objects.ObjectQuery)result).ToTraceString();
The sql generated by the query could be stored and re-used.
Use Sprint.Filter.OData. It converts a Func<T,bool> into string and back to code.
Sample:
public class TestSprintOData
{
public static void Run()
{
// Parse a Func into string
var query = Filter.Serialize<User>(u => u.IsActive && u.Email.Contains("#gmail.com"));
// It'll generate the string "IsActive and substringof('#gmail.com', Email)"
// Convert back to Expression, perhaps on server
var query2 = Filter.Deserialize<User>(query);
// Compiles to Func, so you can use as delegate to Where
var f = query2.Compile();
var list = new List<User>
{
new User{Name="Johnny", IsActive = true, Email = "johnny#gmail.com"},
new User{Name="abc", IsActive = false, Email = ""},
new User{Name="dude", IsActive=true, Email = "dude#gmail.com"}
};
var result = list.Where(f);
}
}
class User
{
public string Name;
public string Phone;
public string Login;
public string Email;
public bool IsActive;
}
You can also use it as a Nuget Package
You may want to consider using Entity SQL rather than LINQ in this case. Entity SQL is a string query that works against your EF conceptual model rather than directly against the database.
I'm breaking my head with this and decided to share my problem with you
I want to create an anonymous select from several tables, some of them may contain more than one result. i want to concatenate these results into one string
i did something like this:
var resultTable = from item in dc.table
select new
{
id= item.id,
name= CreateString((from name in item.Ref_Items_Names
select name.Name).ToList()),
};
and the CreateString() is:
private string CreateString(List<string> list)
{
StringBuilder stringedData = new StringBuilder();
for (int i = 0; i < list.Count; i++)
{
stringedData.Append(list[i] + ", ");
}
return stringedData.ToString();
}
my intentions were to convert the "name" query to list and then sent it to CreateString() to convert it to one long concatenated string.
I tried using .Aggregate((current,next) => current + "," + next);
but when i try to convert my query to DataTable like below:
public DataTable ToDataTable(Object query)
{
DataTable dt = new DataTable();
IDbCommand cmd = dc.GetCommand(query as IQueryable);
SqlDataAdapter adapter = new SqlDataAdapter();
adapter.SelectCommand = (SqlCommand)cmd;
cmd.Connection.Open();
adapter.Fill(dt);
cmd.Connection.Close();
return dt;
}
I'm getting exception that "dc.GetCommand()" can't understand query with Aggregate method
later I tried to even use this simple query:
var resultTable = from itemin dc.table
select new
{
name = CreateString()
};
When CreateString() returns "success", nothing was inserted to "name"
why there is no way of using methods in select clause?
Thank you
Yotam
There is difference between LINQ to objects and LINQ to some-db-provider. Generally speaking, when using IQueryable, you can't use any methods, except the ones your provider understands.
What you can do is to retrieve the data from the database and then do the formatting using LINQ to objects:
var data = from item in dc.table
where /* some condition */
select item;
var result = from item in data.AsEnumerable()
select new
{
name = SomeFunction(item)
}
The AsEnumerable() extension method forces processing using LINQ to objects.
Forgive me if I've miss interpreted your question. It seems that what you are trying to do is abstract your select method for reuse. If this is the case, you may consider projection using a lambda expression. For example:
internal static class MyProjectors
{
internal static Expression<Func<Object1, ReturnObject>> StringDataProjector
{
get
{
return d => new Object1()
{
//assignment here
}
}
}
}
Now you can select your datasets as such:
dc.Table.Select(MyProjectors.StringDataProjector)
As for the concatenation logic, what about selecting to some base class with an IEnumerable<string> property and a read-only property to handle the concatenation of the string?