Incorrect UInt64 ToString SQL generation

[aubiyko]

LINQ query with UInt64.ToString() to MS SQL Server with lagre property value produces flawed SQL code leading to exception.

Steps to reproduce

Suppose simple entity:

    public class DemoEntity
    {
        [Key,
        DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }

        public Int64 LongProperty { get; set; }

        public UInt64 ULongProperty { get; set; }
    }

with simple DbContext using UseSqlServer().

Add-Migration results with LongProperty as bigint and ULongProperty as decimal(20, 0).

ModelSnapshot.BuildModel

modelBuilder
                .HasAnnotation("ProductVersion", "3.1.3")
                .HasAnnotation("Relational:MaxIdentifierLength", 128)
                .HasAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);

            modelBuilder.Entity("ForEFCoreGithubIssue.DemoEntity", b =>
                {
                    b.Property<int>("Id")
                        .ValueGeneratedOnAdd()
                        .HasColumnType("int")
                        .HasAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);

                    b.Property<long>("LongProperty")
                        .HasColumnType("bigint");

                    b.Property<decimal>("ULongProperty")
                        .HasColumnType("decimal(20,0)");

                    b.HasKey("Id");

                    b.ToTable("Data");
                });

Sample database has an least one row with LongProperty equals to Int64.MaxValue and ULongProperty equals to UInt64.MaxValue.

Then query

string needle = "1";
context.Data.Where(x => x.ULongProperty.ToString().Contains(needle))

produces

SELECT [d].[Id], [d].[LongProperty], [d].[ULongProperty]
FROM [Data] AS [d]
WHERE (@__needle_0 = N'') OR (CHARINDEX(@__needle_0, CONVERT(VARCHAR(19), [d].[ULongProperty])) > 0)

that leads to Microsoft.Data.SqlClient.SqlException "Arithmetic overflow error converting numeric to data type varchar.".

Note

Note that

string needle = "1";
context.Data.Where(x => x.LongProperty.ToString().Contains(needle))

produces

SELECT [d].[Id], [d].[LongProperty], [d].[ULongProperty]
FROM [Data] AS [d]
WHERE (@__needle_0 = N'') OR (CHARINDEX(@__needle_0, CONVERT(VARCHAR(20), [d].[LongProperty])) > 0)

that works fine.

The problem is that for ULongProperty generated SQL query assumes 19 character length string, which is too short. Manual row SQL query replaced with VARCHAR(20) works fine.

Further technical details

EF Core version: 3.1.3
Database provider: Microsoft.EntityFrameworkCore.SqlServer v.3.1.3
Target framework: .NET Core 3.1
Operating system: MS Windows 10 1909
IDE: MS VS Community 2019 16.5.1
DB: MS SQL LocalDB 14.0.1000.169