.net core Entity Framework Code firt

public partial class RemoveForeignKey : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_Table1_Table2",
            table: "Table1");

        migrationBuilder.AlterColumn(
            name: "Id",
            table: "Table2",
            nullable: false,
            oldClrType: typeof(int))
            .OldAnnotation("SqlServer:Identity", "1, 1)");

        migrationBuilder.AddColumn(
            name: "Table2Id",
            table: "Table1",
            nullable: false);

        migrationBuilder.AddForeignKey(
            name: "FK_Table1_Table2_Table2Id",
            table: "Table1",
            column: "Table2Id",
            principalTable: "Table2",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_Table1_Table2_Table2Id",
            table: "Table1");

        migrationBuilder.DropColumn(
            name: "Table2Id",
            table: "Table1");

        migrationBuilder.AlterColumn(
            name: "Id",
            table: "Table2",
            nullable: false,
            oldClrType: typeof(int))
            .Annotation("SqlServer:Identity", "1, 1");

        migrationBuilder.AddForeignKey(
            name: "FK_Table1_Table2",
            table: "Table1",
            column: "Table2Id",
            principalTable: "Table2",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);
    }
}

we first drop the foreign key constraint using the DropForeignKey method, then alter the identity column to remove the identity specification using the AlterColumn method. We add the foreign key constraint again using the AddForeignKey method.

To remove a foreign key constraint in migration, you can use the DropForeignKey method followed by the AlterColumn method to remove the foreign key constraint and alter the column to remove the identity specification