11.8 .NET Connector

Contents

• Overview
• Installation
• NuGet (Unified 8.0.55)
• Connection String Reference
• API Reference
• Usage and Examples
• Protocol 4.0-full APIs

Overview

Machbase provides UniMachNetConnector, a universal ADO.NET provider supporting wire protocols 2.1–4.0. The current unified package is UniMachNetConnector 8.0.55, with net452, net5.0, net6.0, net7.0, and net8.0 builds. Automatic negotiation runs only when the connection string specifies PROTOCOL=auto or auto-full.

Installation

Machbase server/client installations distribute the universal .NET provider under $MACHBASE_HOME/lib/. A standard Linux package may include protocol-specific assemblies such as UniMachNetConnector-net50-8.0.55.dll and machNetConnector-40-net50-3.2.2.dll. The source project can build additional target framework variants when the required .NET SDK is available.

• UniMachNetConnector: Framework-independent entry point. Source builds use UniMachNetConnector-net{452|50|60|70|80}-<version>.dll; choose the file matching the deployment framework.
• Legacy protocol connectors: Protocol-specific assemblies such as machNetConnector-XX-net{40|50|60|70|80}-<version>.dll, loaded by UniMachNetConnector as needed.

Reference the DLL matching the application target framework, or deploy it beside the executable.

Multiple Databases

MachConnector 4.0 can select the initial database with DATABASE or DB_NAME in the connection string.

SERVER=127.0.0.1;PORT_NO=5656;UID=APP_A;PWD=secret;DATABASE=FACTORY_A

The standard Database property and ChangeDatabase() are not guaranteed current catalog switching APIs; use SQL USE and CURRENT_DATABASE(). Do not assume automatic catalog reset on return to a connection pool. See the Multi-Database Operations Guide for limitations.

Install with NuGet (Unified Connector, 8.0.55)

The unified connector package ID is UniMachNetConnector. Prefer a NuGet package reference over copying DLLs for new projects.

• Supported TFMs: net452, net5.0, net6.0, net7.0, net8.0
• net5.0 and later builds are self-contained. The net452 source build restores System.ValueTuple 4.5.0.

Command-Line Quick Start

# Run in the project directory
dotnet add package UniMachNetConnector --version 8.0.55
dotnet build

To control the source feed explicitly, add the reference first and restore separately.

dotnet add package UniMachNetConnector --version 8.0.55 --no-restore

# Force a refresh of nuget.org metadata
dotnet nuget locals http-cache --clear
dotnet restore --no-cache --source https://api.nuget.org/v3/index.json

Visual Studio

• Right-click the project → Manage NuGet Packages → Browse → search for “UniMachNetConnector” → select 8.0.55 → Install.

Project File Example

<ItemGroup>
  <PackageReference Include="UniMachNetConnector" Version="8.0.55" />
  <!-- No additional Machbase packages required -->
  <!-- Target frameworks: net452|net5.0|net6.0|net7.0|net8.0 -->
</ItemGroup>

Use a Local or Internal Feed (Optional)

For an internal registry or folder feed, add the source and restore as follows. For a folder feed, place UniMachNetConnector.8.0.55.nupkg in that directory.

# One-time setup
dotnet nuget add source /path/to/local-nuget -n mach-local

# Restore using both the local feed and nuget.org
dotnet restore --no-cache \
  --source /path/to/local-nuget \
  --source https://api.nuget.org/v3/index.json

In environments with restricted permissions, set an absolute package cache path.

PKG_DIR="$(pwd)/.nuget-packages"; mkdir -p "$PKG_DIR"
NUGET_PACKAGES="$PKG_DIR" dotnet restore --no-cache --source /path/to/local-nuget
NUGET_PACKAGES="$PKG_DIR" dotnet run --no-restore

Tip: Immediately after publication, NU1102 (version not found) or “incompatible with ‘all’ frameworks” usually indicates indexing or cache issues. Run dotnet nuget locals http-cache --clear, then restore with --no-cache. The package supports net452 and net5.0–net8.0.

Minimal Example

using System;
using Mach.Data.MachClient;

var password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
    ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required");
var cs = $"SERVER=127.0.0.1;PORT_NO=5656;UID=SYS;PWD={password};PROTOCOL=4.0-full";
using var conn = new MachConnection(cs);
conn.Open();

using var cmd = new MachCommand("SELECT COUNT(*) FROM V$TABLES", conn);
var count = Convert.ToInt64(cmd.ExecuteScalar());
Console.WriteLine($"Tables: {count}");

Connection String Reference

Separate entries with semicolons (;). Keywords listed in the same table row are equivalent.

Example:

var connectionString = string.Format(
    "SERVER={0};PORT_NO={1};UID=SYS;PWD=MANAGER;COMMAND_TIMEOUT=50000;PROTOCOL=4.0-full",
    host,
    port);

Automatic Protocol Detection (PROTOCOL=auto)

With mixed server versions, set PROTOCOL=auto to let UniMachNetConnector negotiate a suitable legacy protocol at runtime:

• PROTOCOL=auto attempts handshakes in order: 4.0 → 3.0 → 2.2 → 2.1. It uses the host, port, user, password, database, and CONNECT_TIMEOUT from the connection string.
• PROTOCOL=auto-full selects the registered 4.0-full descriptor when the server major version is 4. Only builds without that descriptor select limited 4.0. A failed full connection does not automatically retry with limited.
• Multiple hosts, such as SERVER=hostA:5700,hostB:6000, are tried sequentially. Failure messages include each host/protocol combination to aid diagnosis.
• Credentials are uppercased as in legacy drivers. Specify DATABASE= when not using the default database (data).
• CONNECT_TIMEOUT applies to each detection round trip. If the exception says Protocol probe received an invalid response, check the port, firewall, and TLS configuration.

If the server version is known, specify PROTOCOL=2.1, 3.0, 4.0, or 4.0-full to skip automatic detection.

API Reference

MachConnection

public sealed class MachConnection : DbConnection

Manages Machbase connections. Like DbConnection, it implements IDisposable; release it safely with Dispose() or a using statement.

Constructor

MachConnection(string aConnectionString)

Creates a MachConnection from a connection string.

Open

void Open()

Establishes the connection using the connection string.

Close

void Close()

Closes the open connection.

SetConnectAppendFlush

void SetConnectAppendFlush(bool activeFlush)

Sets whether Append flushes automatically.

Fields

MachCommand

public sealed class MachCommand : DbCommand

Executes SQL or Append operations through a MachConnection. Like DbCommand, it implements IDisposable.

Constructors

MachCommand(string aQueryString, MachConnection aConn)

Creates an instance with the SQL to execute and a connection.

MachCommand(MachConnection aConn)

Creates an Append-only command without a query.

CreateParameter

MachParameter CreateParameter()

Creates a new MachParameter.

AppendOpen

MachAppendWriter AppendOpen(
    string aTableName,
    int aErrorCheckCount = 0,
    MachAppendOption option = MachAppendOption.None)

Opens an Append session and returns a MachAppendWriter.

• aTableName: Target table name
• aErrorCheckCount: Sends data and checks failures after the specified record count; sets an automatic APPEND-FLUSH point.
• option: None or MicroSecTruncated.

AppendData

void AppendData(MachAppendWriter writer, List<object> dataList)

Loads list values into the Append buffer in order. Types must match the table columns; too few or too many values raise an exception.

Note: When specifying _arrival_time as ulong, use nanoseconds since 1970-01-01 UTC, as required by Machbase.

void AppendDataWithTime(
    MachAppendWriter writer,
    List<object> dataList,
    DateTime arrivalTime)

Specifies _arrival_time explicitly as DateTime.

void AppendDataWithTime(
    MachAppendWriter writer,
    List<object> dataList,
    ulong arrivalTime)

Specifies _arrival_time as ulong nanoseconds.

AppendFlush

void AppendFlush(MachAppendWriter writer)

Sends buffered data to the server. More frequent calls reduce client-buffered data and transmission delay but may increase communication overhead. A successful call alone does not establish disk durability; also check server processing results and the target table durability policy.

AppendClose

void AppendClose(MachAppendWriter writer)

Closes the Append session. Internally calls AppendFlush() before completing the protocol.

ExecuteNonQuery

int ExecuteNonQuery()

Executes a query and returns the affected-record count. Mainly used for INSERT, UPDATE, DELETE, and DDL.

RowId

UInt64? RowId

After a successful single INSERT ... VALUES in Standard Edition, retrieve the inserted row’s ROWID after ExecuteNonQuery() in MachConnector 4.0/4.0-full and Universal .NET.

using (var command = new MachCommand(
    "INSERT INTO orders(item) VALUES('pump')", connection))
{
    command.ExecuteNonQuery();
    ulong? rowId = command.RowId;
}

Returns null if no ROWID is available. Read the 64-bit RowId, not the legacy 32-bit LastInsertedId. See ROWID and INSERT Result IDs for differences in batches and Append.

ExecuteScalar

object ExecuteScalar()

Executes a query and returns the first column value.

ExecuteDbDataReader

DbDataReader ExecuteDbDataReader(CommandBehavior behavior)

Executes a query and returns a DbDataReader for sequential result access.

Fields

MachDataReader

public sealed class MachDataReader : DbDataReader

Reads fetched results sequentially. Use only objects obtained from MachCommand.ExecuteDbDataReader().

GetName

string GetName(int ordinal)

Returns the column name at the specified index.

GetDataTypeName

string GetDataTypeName(int ordinal)

Returns the Machbase column type name.

GetFieldType

Type GetFieldType(int ordinal)

Returns the mapped .NET type.

GetOrdinal

int GetOrdinal(string name)

Returns the index for a column name.

GetValue

object GetValue(int ordinal)

Returns the current record value as object.

IsDBNull

bool IsDBNull(int ordinal)

Checks whether the column value is NULL.

GetValues

int GetValues(object[] values)

Fills an array with current record values and returns the number of entries written.

GetSchemaTable

DataTable GetSchemaTable()

Returns schema metadata for SELECT result columns. Check AllowDBNull for nullability. This behavior applies to both MachConnector40 and MachConnector40-full-API.

using var reader = command.ExecuteReader();
DataTable schema = reader.GetSchemaTable();

foreach (DataRow row in schema.Rows)
{
    string columnName = Convert.ToString(row["ColumnName"]);
    object allowDBNull = row["AllowDBNull"];

    if (allowDBNull is bool value && !value)
    {
        Console.WriteLine($"{columnName}: NO_NULLS");
    }
    else
    {
        // true or DBNull.Value: NULL handling required
        Console.WriteLine($"{columnName}: NULL handling required");
    }
}

DBNull.Value does not mean NOT NULL; handle it as potentially nullable. See Nullable Metadata Support for SQL result rules.

In Machbase SQL, '' is SQL NULL: AllowDBNull in GetSchemaTable() is true, and IsDBNull() is true for the row. The literal '''' is one single quote character, a non-NULL string result with AllowDBNull=false.

GetSchemaTable() provides ColumnName, ColumnOrdinal, ColumnSize, NumericPrecision, NumericScale, DataType, ProviderType, IsLong, AllowDBNull, and IsKey. IsKey=true identifies a direct SELECT result column that is a PRIMARY KEY. Expressions and aggregates report false.

Older servers or SDKs may return false for IsKey.

Nullable metadata does not change DECIMAL precision 1–65, scale 0–30, or actual values. .NET returns DECIMAL as System.Decimal when precision is at most 29 and scale is at most 28. Values beyond that range return System.String to prevent precision loss. In that case, GetSchemaTable().DataType, GetFieldType(), and the actual row value CLR type are all System.String.

GetXXXX

bool GetBoolean(int ordinal)
byte GetByte(int ordinal)
char GetChar(int ordinal)
short GetInt16(int ordinal)
int GetInt32(int ordinal)
long GetInt64(int ordinal)
DateTime GetDateTime(int ordinal)
string GetString(int ordinal)
decimal GetDecimal(int ordinal)
double GetDouble(int ordinal)
float GetFloat(int ordinal)

Returns the column value as the specified type.

Read

bool Read()

Reads the next record. Returns false when there are no more results.

Fields

MachParameterCollection

public sealed class MachParameterCollection :
    DbParameterCollection,
    IEnumerable<MachParameter>

Manages parameters bound to a MachCommand.

Set parameters before execution to send their values with the command.

MachParameter binding does not provide a Prepared Statement execution-plan cache. Measure repeated execution with actual queries and server cache conditions.

The current provider renders parameters as typed SQL literals and executes through ExecDirect. MachParameterCollection therefore does not use the server Prepared Named Bind protocol or parameter metadata.

Add

MachParameter Add(string parameterName, DbType dbType)

Adds a MachParameter with the specified name and type, and returns it.

int Add(object value)

Adds a value and returns its index.

void AddRange(Array values)

Adds an array of plain values in one call.

MachParameter AddWithValue(string parameterName, object value)

Adds a parameter name and value, and returns the created MachParameter.

Contains

bool Contains(object value)

Checks whether the value has already been added.

bool Contains(string parameterName)

Checks whether the specified parameter name exists.

Clear

void Clear()

Removes all parameters.

IndexOf

int IndexOf(object value)

Returns the index of the value.

int IndexOf(string parameterName)

Returns the index of the parameter name.

Insert

void Insert(int index, object value)

Inserts a value at the specified position.

Remove

void Remove(object value)

Removes the parameter containing the value.

void RemoveAt(int index)

Removes the parameter at the index.

void RemoveAt(string parameterName)

Removes the parameter with the specified name.

Fields

MachParameter

public sealed class MachParameter : DbParameter

Stores binding information for one parameter.

Fields

MachException

public class MachException : DbException

Exception class for Machbase errors.

Fields

MachAppendWriter

public sealed class MachAppendWriter

Helper class for the Append protocol. Obtain an instance by calling MachCommand.AppendOpen().

SetErrorDelegator

void SetErrorDelegator(ErrorDelegateFuncType callback)

void ErrorDelegateFuncType(MachAppendException e);

Registers a delegate called on Append errors.

Fields

MachAppendException

public sealed class MachAppendException : MachException

Exception with additional Append error information. Preserves the server error message and exposes the failed record as a string.

GetRowBuffer

string GetRowBuffer()

Returns the original failed record as a string.

Usage and Examples

Connect

This example connects with an environment-variable password, creates a LOG table, inserts and queries data, then drops the table.

using System;
using Mach.Data.MachClient;

var password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
    ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required");
var connString = $"SERVER=127.0.0.1;PORT_NO=5656;UID=SYS;PWD={password};PROTOCOL=4.0-full";
using var connection = new MachConnection(connString);
connection.Open();
const string tableName = "NET_QUERY_DEMO";

using (var create = new MachCommand(
    $"CREATE LOG TABLE {tableName} (id INTEGER, name VARCHAR(40))", connection))
{
    create.ExecuteNonQuery();
}
try
{
    using (var insert = new MachCommand(
        $"INSERT INTO {tableName} VALUES (1, 'pump')", connection))
    {
        insert.ExecuteNonQuery();
    }
    using var query = new MachCommand($"SELECT id, name FROM {tableName}", connection);
    using var reader = query.ExecuteReader();
    while (reader.Read())
    {
        for (var column = 0; column < reader.FieldCount; column++)
        {
            Console.WriteLine($"{reader.GetName(column)} : {reader.GetValue(column)}");
        }
    }
}
finally
{
    using var drop = new MachCommand($"DROP TABLE {tableName}", connection);
    drop.ExecuteNonQuery();
}

Parameter Binding

MachParameterCollection supports :name, @name, and ?name placeholders. Prefer :name, which matches common SQL syntax. Name lookup is case-insensitive; a repeated name applies one value to all matching positions.

Use :name with Machbase 8.7.0 servers. Older servers raise MachException. @name and ?name are legacy provider compatibility formats.

var password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
    ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required");
var connString = $"SERVER=127.0.0.1;PORT_NO=5656;UID=SYS;PWD={password};PROTOCOL=4.0-full";
using var connection = new MachConnection(connString);
connection.Open();

const string sql = @"
    SELECT NAME
      FROM V$TABLES
     WHERE NAME = :table_name OR NAME = :table_name";

using var command = new MachCommand(sql, connection);

command.Parameters.AddWithValue(":table_name", "V$TABLES");

using var reader = command.ExecuteReader();
while (reader.Read())
{
    Console.WriteLine($"{reader.GetName(0)} : {reader.GetValue(0)}");
}

Pass NULL as DBNull.Value. See Named Bind Parameter Syntax for shared name syntax.

Append

Use the Append protocol to load large volumes of time-series data quickly.

using System;
using System.Collections.Generic;
using Mach.Data.MachClient;

var password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
    ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required");
var connString = $"SERVER=127.0.0.1;PORT_NO=5656;UID=SYS;PWD={password};PROTOCOL=4.0-full";
using var connection = new MachConnection(connString);
connection.Open();

const string tableName = "NET_APPEND_DEMO";
using (var create = new MachCommand(
    $"CREATE LOG TABLE {tableName} (ID INTEGER, NAME VARCHAR(40))", connection))
{
    create.ExecuteNonQuery();
}

try
{
using var appendCommand = new MachCommand(connection);
var writer = appendCommand.AppendOpen(tableName);
writer.SetErrorDelegator(error =>
    Console.Error.WriteLine($"Append row error: {error.Message}\n{error.GetRowBuffer()}"));

try
{
    for (var i = 1; i <= 100000; i++)
    {
        appendCommand.AppendData(writer, new List<object> { i, $"NAME_{i % 100}" });
        if (i % 1000 == 0) appendCommand.AppendFlush(writer);
    }
}
finally
{
    if (appendCommand.IsAppendOpened) appendCommand.AppendClose(writer);
}

Console.WriteLine($"Success Count : {writer.SuccessCount}");
Console.WriteLine($"Failure Count : {writer.FailureCount}");
if (writer.FailureCount != 0)
    throw new InvalidOperationException($"Append failed rows: {writer.FailureCount}");
}
finally
{
    if (connection.State == System.Data.ConnectionState.Open)
    {
        try
        {
            using var drop = new MachCommand($"DROP TABLE {tableName}", connection);
            drop.ExecuteNonQuery();
        }
        catch (Exception cleanupError)
        {
            Console.Error.WriteLine($"cleanup failed: {cleanupError.Message}");
        }
    }
}

ARRAY and Selected-Column Append

Machbase DBMS 8.7.0 full/legacy providers return ARRAY as object[]. Element NULL is null within the array; use IsDBNull() to identify whole-array NULL.

Standard AppendOpen(table) can also accept MachSparseArray as an ARRAY column value.

var writer = append.AppendOpen("ARRAY_APPEND_FULL_EXAMPLE");

Input rows follow table column order. The standard Open example inserts sparse values, empty sparse arrays, and whole NULL into ID LONG, A INT32[4], covering AppendData(), Close, and result checks.

The IList<string> overload of AppendOpen() accepts ordinary columns or ARRAY_COLUMN[position]. To vary positions by row, pass MachSparseArray to a whole-array target. Element targets and MachSparseArray.Set() positions are 0-based.

using var append = new MachCommand(connection);
var writer = append.AppendOpen(
    "ARRAY_APPEND_EXAMPLE",
    new List<string> { "ID", "A" });
var sparse = new MachSparseArray(MachDBType.INT32_ARRAY, 4)
    .Set(1, 200)
    .Set(3, 400);

try
{
    append.AppendData(writer, new List<object> { 2L, sparse });
}
finally
{
    if (append.IsAppendOpened)
        append.AppendClose(writer);
}

An empty MachSparseArray means an ARRAY with all NULL elements; DBNull.Value means whole-array NULL. See Sparse ARRAY and Selected-Column Append API for overloads and complete validation examples.

Configure the Error Delegate

Register the delegate immediately after opening the writer to receive row errors as in the example above. Check success/failure counts after close.

Configure Automatic AppendFlush

AppendOpen starts an automatic flush thread. To disable it, call connection.SetConnectAppendFlush(false) on an already open writer. Automatic thread errors may not immediately surface as public exceptions; retain explicit flush/close and callback/count checks.

Protocol 4.0-full APIs

PROTOCOL=4.0-full enables expanded ADO.NET APIs. In the 8.0.55 source package, the 4.0 limited connector is 3.1.3 and 4.0-full is 3.2.2. Linux installations may include only the net50 variant under $MACHBASE_HOME/lib/; use source builds or NuGet restore artifacts for other target frameworks.

• UniMachNetConnector-net50-8.0.55.dll – Universal entry point commonly installed with the DBMS Standard Linux package
• machNetConnector-40-net50-3.1.3.dll – Protocol 4.0 limited connector
• machNetConnector-40-net50-3.2.2.dll – Protocol 4.0-full connector

Main Types Added in 4.0-full

• MachDbProviderFactory: Registers/creates the provider with invariant name Mach.Data.
• MachConnectionStringBuilder: Constructs connection strings without keyword typos.
• MachDataAdapter, MachRowUpdating, MachRowUpdated: Support DataTable/DataSet workflows.
• MachCommandBuilder: Generates INSERT/DELETE (and UPDATE under certain conditions) from SELECT. Before execution, check that generated SQL complies with the target table DML restrictions.

Enable the Full API

var password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
    ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required");
var connString =
    $"SERVER=127.0.0.1;PORT_NO=5656;UID=SYS;PWD={password};PROTOCOL=4.0-full";
using var connection = new MachConnection(connString);
connection.Open();

For UPDATE/DELETE, check both table-specific requirements and driver SQL generation capabilities. LOG does not support UPDATE. TAG UPDATE in Machbase DBMS 8.7.0 Standard Edition requires NAME and BASETIME predicates. Use commands and bindings that follow TAG UPDATE Syntax instead of relying on generic CommandBuilder output.

Use the Connection String Builder

var builder = new MachConnectionStringBuilder
{
    Server = "127.0.0.1",
    Port = 5656,
    UserID = "SYS",
    Password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
        ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required")
};

builder["PROTOCOL"] = "4.0-full";

using var connection = new MachConnection(builder.ConnectionString);
connection.Open();

Example: SQL INSERT with MachDataAdapter

Load a LOOKUP table into a DataTable and add a row; the command builder executes an ordinary SQL INSERT. This path does not use the Append protocol.

using Mach.Data.MachClient;
using System;
using System.Data;

var password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
    ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required");
var connString =
    $"SERVER=127.0.0.1;PORT_NO=5656;UID=SYS;PWD={password};PROTOCOL=4.0-full";
using var connection = new MachConnection(connString);
connection.Open();

using (var create = new MachCommand(
    "CREATE LOOKUP TABLE dotnet_lookup_demo (id INTEGER PRIMARY KEY, name VARCHAR(80))",
    connection))
{
    create.ExecuteNonQuery();
}

var adapter = new MachDataAdapter(
    "SELECT id, name FROM dotnet_lookup_demo ORDER BY id",
    connection);
var builder = new MachCommandBuilder(adapter);

var table = new DataTable();
adapter.Fill(table);

var newRow = table.NewRow();
newRow["id"] = 2001;
newRow["name"] = "Inserted from MachDataAdapter";
table.Rows.Add(newRow);

adapter.MachRowUpdating += (sender, args) =>
{
    Console.WriteLine(
        $"About to run {args.StatementType} with SQL: {args.Command?.CommandText}");
};

adapter.Update(table);

using var drop = new MachCommand("DROP TABLE dotnet_lookup_demo", connection);
drop.ExecuteNonQuery();

Tip: To inspect SQL before transmission, subscribe to events before Update(), as above.

Example: Use DbProviderFactory

MachDbProviderFactory.Instance connects Machbase to provider-neutral configurations such as DbProviderFactories and Dapper.

using System;
using System.Data.Common;
using Mach.Data.MachClient;

DbProviderFactory factory = MachDbProviderFactory.Instance;

using DbConnection connection = factory.CreateConnection()!;
var password = Environment.GetEnvironmentVariable("MACHBASE_PASSWORD")
    ?? throw new InvalidOperationException("MACHBASE_PASSWORD is required");
connection.ConnectionString =
    $"SERVER=127.0.0.1;PORT_NO=5656;UID=SYS;PWD={password};PROTOCOL=4.0-full";
connection.Open();

using DbCommand command = connection.CreateCommand();
command.CommandText = "SELECT COUNT(*) FROM V$TABLES";
var count = (long)command.ExecuteScalar();

Console.WriteLine($"Visible tables: {count}");

For automatic factory discovery in configuration-based applications, call MachDbProviderFactory.Register() once at startup so that DbProviderFactories.GetFactory("Mach.Data") returns the same instance.

Protocol 4.0-full requires Machbase 7.x or later. For older servers, use PROTOCOL=4.0 (limited features) or protocols 2.x/3.x.