Efcore: Exception when scaffolding SQLite databases with columns with no a declared type

[Starkie]

Hi again!
This is a similar bug that the one reported at #13528.

Apparently, in SQLite the type declaration of a column is optional (explained at the _Column Definitions_ section of the link). So, CREATE TABLE data(key PRIMARY KEY);, omitting the column type, is a valid expression to create a table.

I tried to create the scaffold of a table with a column that has no declared type. Using the dotnet ef dbcontext scaffold, the following exception is thrown:

Exception message: System.ArgumentException: The string argument 'storeTypeName' cannot be empty.
Stack trace: at Microsoft.EntityFrameworkCore.Utilities.Check.NotEmpty(String value, String parameterName)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingInfo..ctor(String storeTypeName)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindMapping(String storeTypeName)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ScaffoldingTypeMapper.FindMapping(String storeType, Boolean keyOrIndex, Boolean rowVersion)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.GetTypeScaffoldingInfo(DatabaseColumn column)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitColumn(EntityTypeBuilder builder, DatabaseColumn column)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitColumns(EntityTypeBuilder builder, ICollection`1 columns)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTable(ModelBuilder modelBuilder, DatabaseTable table)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTables(ModelBuilder modelBuilder, ICollection`1 tables)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitDatabaseModel(ModelBuilder modelBuilder, DatabaseModel databaseModel)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.Create(DatabaseModel databaseModel, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineerScaffolder.ScaffoldModel(String connectionString, IEnumerable`1 tables, IEnumerable`1 schemas, String namespace, String language, String contextDir, String contextName, ModelReverseEngineerOptions modelOptions, ModelCodeGenerationOptions codeOptions)
   at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String outputContextDir, String dbContextClassName, IEnumerable`1 schemas, IEnumerable`1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String outputDbContextDir, String dbContextClassName, IEnumerable`1 schemaFilters, IEnumerable`1 tableFilters, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_1.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
The string argument 'storeTypeName' cannot be empty.

Steps to reproduce

I created a small project to repro it: ScaffoldEmptyType.zip

It consist of a database test.db with the schema:

CREATE TABLE data(key PRIMARY KEY);

Then, executing the following command will cause the exception.

$ dotnet ef dbcontext scaffold "DataSource=test.db" Microsoft.EntityFrameworkCore.Sqlite

Further technical details

EF Core version: 2.1.3
Database Provider: Microsoft.EntityFrameworkCore.Sqlite
Operating system: Ubuntu 18.04.1 LTS
IDE: VS Code 1.27.2

[Starkie]

It seems to be related to #13253, which might solve this issue: Implementing the type fallback to blob might avoid the type to be null.

[ajcvickers]

Triage: allow empty-string type names. :trollface:

[Starkie]

That was a 10/10 commit message. Thanks for solving it so fast! 👍

[tgutzler]

Hi,
I'm getting the same error when trying to scaffold a sqlite database (schema attached) with 2.2.0-preview2-35157.
However, looking at the schema, I don't see a table that has rows without a defined type. Am I missing it or is there another problem?

PM> Scaffold-DbContext "Filename=homebudget.db" Microsoft.EntityFrameworkCore.Sqlite
System.ArgumentException: The string argument 'storeTypeName' cannot be empty.
at Microsoft.EntityFrameworkCore.Utilities.Check.NotEmpty(String value, String parameterName)
at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingInfo..ctor(String storeTypeName)
at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindMapping(String storeTypeName)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ScaffoldingTypeMapper.FindMapping(String storeType, Boolean keyOrIndex, Boolean rowVersion)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.GetTypeScaffoldingInfo(DatabaseColumn column)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitColumn(EntityTypeBuilder builder, DatabaseColumn column)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitColumns(EntityTypeBuilder builder, ICollection1 columns) at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTable(ModelBuilder modelBuilder, DatabaseTable table) at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitTables(ModelBuilder modelBuilder, ICollection1 tables)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.VisitDatabaseModel(ModelBuilder modelBuilder, DatabaseModel databaseModel)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.RelationalScaffoldingModelFactory.Create(DatabaseModel databaseModel, Boolean useDatabaseNames)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineerScaffolder.ScaffoldModel(String connectionString, IEnumerable1 tables, IEnumerable1 schemas, String namespace, String language, String contextDir, String contextName, ModelReverseEngineerOptions modelOptions, ModelCodeGenerationOptions codeOptions)
at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String outputContextDir, String dbContextClassName, IEnumerable1 schemas, IEnumerable1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String outputDbContextDir, String dbContextClassName, IEnumerable1 schemaFilters, IEnumerable1 tableFilters, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_1.<.ctor>b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
The string argument 'storeTypeName' cannot be empty.

db.txt

[ajcvickers]

@tgutzler "...screenMajor INTEGER, _screenMinor_, screenMini INTEGER..."

[mpearon]

Hey, @tgutzler - Where did you get the P/W for the HomeBudget sqlite DB?