BulkInsert

This method inserts all rows from the client application into the database in bulk. It is supported for EnterpriseDB.

This page documents the EnterpriseDB-specific arguments and examples. For the SQL Server implementation, see BulkInsert (SQL Server).

Call Flow Diagram

The diagram below shows the flow when calling this operation.

flowchart TD
    Client["Client<br/>(RepoDB)"] -->|BulkInsert| Source["Entities /<br/>DataTable /<br/>DbDataReader"]
    Source --> Decision{"identityBehavior ==<br/>ReturnIdentity?"}
    Decision -->|NO| Direct["EDBBulkCopy<br/>(Npgsql binary COPY)"]
    Direct -->|Write| Table[("Target Table")]
    Decision -->|YES| Pseudo["Create Pseudo Table<br/>(Auto/Memory/Physical)"]
    Pseudo --> Staged["EDBBulkCopy<br/>(Npgsql binary COPY)"]
    Staged -->|Write| PseudoTable[("Pseudo Table")]
    PseudoTable --> Insert["INSERT INTO Target (...)<br/>SELECT ... FROM Pseudo<br/>ORDER BY row-order<br/>RETURNING Id"]
    Insert --> Table
    Insert -->|"Assign identity onto<br/>entities[i] in read order"| Client
    PseudoTable -->|Drop| Cleanup(["Pseudo Table Dropped"])

Use Case

Use this method to insert rows against EnterpriseDB at high speed. It leverages RepoDb.Connector.EnterpriseDb’s EDBBulkCopy, itself built on top of Npgsql’s native binary COPY protocol — a genuine bulk load, not a client-side loop of single-row statements.

Rows are written straight into the target table. A pseudo (staging) table is only used when identityBehavior is set to ReturnIdentity (see below), so the generated identity values can be read back — see Operations (EnterpriseDB) for the underlying mechanics.

Special Arguments

The mappings, bulkCopyTimeout, batchSize, identityBehavior and pseudoTableType arguments are available for this operation.

mappings (via EDBBulkInsertMapItem) defines explicit column mappings between the source properties and the destination columns, with an optional EDBType override per mapping. When omitted, columns are auto-mapped by name (case-insensitive). Mismatched source/destination CLR types throw an InvalidTypeException up front.

bulkCopyTimeout overrides the command timeout, in seconds, applied to the underlying EDBBulkCopy write.

batchSize overrides the number of rows written per batch. When not set, the provider’s default batch size is used.

identityBehavior (via EDBBulkImportIdentityBehavior) controls whether newly generated identity values are set back on the data entities. Disabled (KeepIdentity) by default. Enabling this (ReturnIdentity) routes the operation through a pseudo table instead.

pseudoTableType (via EDBBulkImportPseudoTableType) controls the kind of staging table used when identityBehavior is ReturnIdentity — Auto (default) picks Physical once the row count reaches the internal threshold (5000), otherwise Memory; Memory backs the operation with a session-private temporary table; Physical backs it with an ordinary heap table shared across calls.

The DbDataReader overload has no identityBehavior argument — a forward-only, single-pass reader cannot be rewound to correlate generated identity values back onto a source row. Its pseudoTableType argument is likewise unused, kept only for signature symmetry with the other bulk operations.

Identity Setting Alignment

When identityBehavior is ReturnIdentity, the pseudo table gets an extra __RepoDbBulkRowOrder__ identity column recording each row’s original load position. After staging completes, the library runs:

> INSERT INTO "OriginalTable" (Field1, Field2, ...)
> SELECT Field1, Field2, ... FROM "PseudoTable" ORDER BY "__RepoDbBulkRowOrder__"
> RETURNING "Id" AS "Result";

Results are then read back in that same row-order and assigned positionally onto the matching entity or DataRow.

Usability

The following example defines a method that produces a list of Person objects, then bulk-inserts 10,000 rows into the Person table.

private IEnumerable<Person> GetPeople(int count = 1000)
{
    for (var i = 0; i < count; i++)
    {
        yield return new Person
        {
            Name = $"Person-{i}",
            Age = 30,
            CreatedDateUtc = DateTime.UtcNow
        };
    }
}

using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000);
    var insertedRows = connection.BulkInsert(people);
}

To specify a batch size:

using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000);
    var insertedRows = connection.BulkInsert(people, batchSize: 100);
}

To return the newly generated identity values:

using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000); // Id not set
    var insertedRows = connection.BulkInsert(people,
        identityBehavior: EDBBulkImportIdentityBehavior.ReturnIdentity);
    // people[i].Id now holds the generated identity for each row
}

DataTable

using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000);
    var table = ConvertToDataTable(people);
    var insertedRows = connection.BulkInsert("\"Person\"", table);
}

Dictionary/ExpandoObject

using (var sourceConnection = new EDBConnection(sourceConnectionString))
{
    var result = sourceConnection.QueryAll("\"Person\"");
    using (var destinationConnection = new EDBConnection(destinationConnectionString))
    {
        var insertedRows = destinationConnection.BulkInsert("\"Person\"", result);
    }
}

DataReader

using (var sourceConnection = new EDBConnection(sourceConnectionString))
{
    using (var reader = sourceConnection.ExecuteReader("SELECT * FROM \"Person\""))
    {
        using (var destinationConnection = new EDBConnection(destinationConnectionString))
        {
            var insertedRows = destinationConnection.BulkInsert("\"Person\"", reader);
        }
    }
}

To bulk-insert via DataEntityDataReader:

using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000);
    using (var reader = new DataEntityDataReader<Person>(people))
    {
        var insertedRows = connection.BulkInsert("\"Person\"", reader);
    }
}

Column Mappings

Add column mappings using the EDBBulkInsertMapItem class.

var mappings = new List<EDBBulkInsertMapItem>();

// Add the mappings
mappings.Add(new EDBBulkInsertMapItem("SourceId", "DestinationId"));
mappings.Add(new EDBBulkInsertMapItem("SourceName", "DestinationName"));
mappings.Add(new EDBBulkInsertMapItem("SourceAge", "DestinationAge"));
mappings.Add(new EDBBulkInsertMapItem("SourceCreatedDateUtc", "DestinationCreatedDateUtc"));

// Execute
using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000);
    var insertedRows = connection.BulkInsert(people,
        mappings: mappings);
}

Targeting a Table

To target a specific table, pass the literal table name.

using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000);
    var insertedRows = connection.BulkInsert("\"Person\"", people);
}

Async Method

An equivalent BulkInsertAsync method is also available.

using (var connection = new EDBConnection(connectionString))
{
    var people = GetPeople(10000);
    var insertedRows = await connection.BulkInsertAsync(people);
}