dotnet/efcore · error · InvalidOperationException

The number of column types

Error message

The number of column types ({typesCount}) doesn't match the number of columns ({columnsCount}) for the data insertion operation on '{table}'. Provide the same number of column types and columns.

What it means

For an InsertDataOperation where ColumnTypes is provided, EF checks that ColumnTypes.Length equals Columns.Length. Column types let the generator emit typed SQL when no model is available; an uneven list would leave some columns untyped or misaligned, so EF rejects it.

Solutions

1. Provide exactly one column type per entry in columns, in the same order.
2. Regenerate the migration so EF emits consistent columns/columnTypes.
3. Drop columnTypes entirely if a model is attached (EF infers types), which also avoids this check.

Example fix

// before
migrationBuilder.InsertData(
    table: "Products",
    columns: new[] { "Id", "Name" },
    columnTypes: new[] { "int" },
    values: new object[,] { { 1, "A" } });

// after
migrationBuilder.InsertData(
    table: "Products",
    columns: new[] { "Id", "Name" },
    columnTypes: new[] { "int", "nvarchar(100)" },
    values: new object[,] { { 1, "A" } });

// Validate column types align with columns for InsertData
static void ValidateInsertTypes(InsertDataOperation op)
{
    if (op.ColumnTypes is { } types && types.Length != op.Columns.Length)
        throw new ArgumentException(
            $"InsertData on {op.Table}: {types.Length} types vs " +
            $"{op.Columns.Length} columns.");
}

static bool InsertTypesOk(InsertDataOperation op)
    => op.ColumnTypes is null || op.ColumnTypes.Length == op.Columns.Length;

When it happens

Trigger: migrationBuilder.InsertData(..., columns: new[] { "A","B" }, columnTypes: new[] { "int" }, ...) — the columnTypes array is shorter/longer than columns. Common in hand-written migrations or when a column was added without updating the types array.

Common situations: Editing a migration file by hand; programmatically generating InsertData where types and columns come from different sources; cross-provider migration where types were specified explicitly.

Related errors

• The data insertion operation on
• The number of key values
• The number of values
• A seed entity for entity type
• A seed entity for entity type

AI-assisted analysis of dotnet/efcore@3a2006ef56 (2026-08-11). Data as JSON: /api/errors/193f9645298e6829. Report an issue: GitHub.

Appendix: source

Thrown at src/EFCore.Relational/Migrations/MigrationsSqlGenerator.cs:884

    /// <param name="operation">The data operation to generate commands for.</param>
    /// <param name="model">The model.</param>
    /// <returns>The commands that correspond to the given operation.</returns>
    protected virtual IEnumerable<IReadOnlyModificationCommand> GenerateModificationCommands(
        InsertDataOperation operation,
        IModel? model)
    {
        if (operation.Columns.Length != operation.Values.GetLength(1))
        {
            throw new InvalidOperationException(
                RelationalStrings.InsertDataOperationValuesCountMismatch(
                    operation.Values.GetLength(1), operation.Columns.Length,
                    FormatTable(operation.Table, operation.Schema ?? model?.GetDefaultSchema())));
        }

        if (operation.ColumnTypes != null
            && operation.Columns.Length != operation.ColumnTypes.Length)
        {
            throw new InvalidOperationException(
                RelationalStrings.InsertDataOperationTypesCountMismatch(
                    operation.ColumnTypes.Length, operation.Columns.Length,
                    FormatTable(operation.Table, operation.Schema ?? model?.GetDefaultSchema())));
        }

        if (operation.ColumnTypes == null
            && model == null)
        {
            throw new InvalidOperationException(
                RelationalStrings.InsertDataOperationNoModel(
                    FormatTable(operation.Table, operation.Schema ?? model?.GetDefaultSchema())));
        }

        var propertyMappings = operation.ColumnTypes == null
            ? GetPropertyMappings(operation.Columns, operation.Table, operation.Schema, model)
            : null;

        for (var i = 0; i < operation.Values.GetLength(0); i++)

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