dotnet/efcore · error · InvalidOperationException

The number of value rows ({valuesCount}) doesn't match the n

Error message

The number of value rows ({valuesCount}) doesn't match the number of key rows ({keyCount}) for the data modification operation on '{table}'. Provide the same number of value rows and key rows.

What it means

Thrown inside GenerateModificationCommands(UpdateDataOperation, ...) in src/EFCore.Relational/Migrations/MigrationsSqlGenerator.cs:1074 (message key UpdateDataOperationRowCountMismatch). It compares operation.KeyValues.GetLength(0) against operation.Values.GetLength(0) and throws InvalidOperationException when they differ. UpdateData pairs each key row with one value row (UPDATE ... WHERE key = ...), so the number of key rows must equal the number of value rows.

Source

Thrown at src/EFCore.Relational/Migrations/MigrationsSqlGenerator.cs:1074

        IModel? model)
    {
        if (operation.KeyColumns.Length != operation.KeyValues.GetLength(1))
        {
            throw new InvalidOperationException(
                RelationalStrings.UpdateDataOperationKeyValuesCountMismatch(
                    operation.KeyValues.GetLength(1), operation.KeyColumns.Length, FormatTable(operation.Table, operation.Schema)));
        }

        if (operation.Columns.Length != operation.Values.GetLength(1))
        {
            throw new InvalidOperationException(
                RelationalStrings.UpdateDataOperationValuesCountMismatch(
                    operation.Values.GetLength(1), operation.Columns.Length, FormatTable(operation.Table, operation.Schema)));
        }

        if (operation.KeyValues.GetLength(0) != operation.Values.GetLength(0))
        {
            throw new InvalidOperationException(
                RelationalStrings.UpdateDataOperationRowCountMismatch(
                    operation.Values.GetLength(0), operation.KeyValues.GetLength(0), FormatTable(operation.Table, operation.Schema)));
        }

        if (operation.KeyColumnTypes != null
            && operation.KeyColumns.Length != operation.KeyColumnTypes.Length)
        {
            throw new InvalidOperationException(
                RelationalStrings.UpdateDataOperationKeyTypesCountMismatch(
                    operation.KeyColumnTypes.Length, operation.KeyColumns.Length, FormatTable(operation.Table, operation.Schema)));
        }

        if (operation.ColumnTypes != null
            && operation.Columns.Length != operation.ColumnTypes.Length)
        {
            throw new InvalidOperationException(
                RelationalStrings.UpdateDataOperationTypesCountMismatch(
                    operation.ColumnTypes.Length, operation.Columns.Length, FormatTable(operation.Table, operation.Schema)));

View on GitHub (pinned to dbf9771522)

Solutions

1. Ensure operation.Values.GetLength(0) == operation.KeyValues.GetLength(0) (one value row per key row).
2. Re-scaffold the migration so rows stay paired.
3. Manage seed data with HasData so EF keeps key rows and value rows aligned.
4. Audit: assert values.GetLength(0) == keyValues.GetLength(0) for each UpdateData.

Example fix

// before (2 key rows, 1 value row):
migrationBuilder.UpdateData(
    table: "Users",
    keyColumns: new[] { "Id" },
    keyValues: new object[,] { { 1 }, { 2 } },
    columns: new[] { "Name" },
    values: new object[,] { { "Alice" } });

// after (paired rows):
migrationBuilder.UpdateData(
    table: "Users",
    keyColumns: new[] { "Id" },
    keyValues: new object[,] { { 1 }, { 2 } },
    columns: new[] { "Name" },
    values: new object[,] { { "Alice" }, { "Bob" } });

static bool UpdateRowCountIsValid(object[,] keyValues, object[,] values)
{
    return keyValues.GetLength(0) == values.GetLength(0);
}

// usage before calling migrationBuilder.UpdateData
if (!UpdateRowCountIsValid(keyValues, values))
    throw new InvalidOperationException("number of value rows must equal number of key rows");

try
{
    await dbContext.Database.MigrateAsync();
}
catch (InvalidOperationException ex) when (ex.Message.Contains("number of value rows") && ex.Message.Contains("data modification"))
{
    logger.LogError(ex, "An UpdateDataOperation has mismatched key/value row counts; fix the migration.");
    throw;
}

When it happens

Trigger: A migration calls migrationBuilder.UpdateData where the number of key rows in keyValues differs from the number of value rows in values. For example keyValues has 2 rows ({1},{2}) but values has 1 row ({"x"}). Happens when editing an UpdateData to add/remove a row on only one side.

Common situations: Hand-editing an UpdateData and adding a key row without its value row (or vice versa). Scaffolded multi-row HasData update that was partially edited. Misaligned batch updates in hand-authored migrations.

Related errors

• The number of key values ({valuesCount}) doesn't match the n
• The number of values ({valuesCount}) doesn't match the numbe
• The number of key column types ({typesCount}) doesn't match
• The number of column types ({typesCount}) doesn't match the
• The number of values ({valuesCount}) doesn't match the numbe

AI-assisted analysis of dotnet/efcore@dbf9771522 (2026-08-06). Data as JSON: /api/errors/b8a23ed2b9a8593a. Report an issue: GitHub.