There seems problems about tt script generate MySQL model

I’ve installed MySQL 5.6 server on my Windows 7 OS. I use Visual Studio 2010 to develop software and download the linq2db from NuGet.

After I Installed the “LINQ to DB” , “LINQ to DB T4 Models” and “LINQ to MySql” , I copy the “CopyMe.MySql.tt.txt” to the Models folder(I develop an ASP.Net MVC project). Then I modify the file name to “CopyMe.MySql.tt” and modify the LoadMySqlMetadata method with correct data like below.

LoadMySqlMetadata(“localhost”, “world”, “root”, “mypassword”);

the “world” database is default generated by MySQL installer.

After I modify the LoadMySqlMetadata Method and saved the .tt script file.

It generate some error like below.

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錯誤 1 正在執行轉換: System.InvalidOperationException: 序列未包含項目 於 System.Linq.Enumerable.Max(IEnumerable1 source) 於 System.Linq.Enumerable.Max[TSource](IEnumerable1 source, Func`2 selector) 於 Microsoft.VisualStudio.TextTemplating77DC7F2B06966E27F1DD4AC0DBECEEC6.GeneratedTextTransformation.GenerateTypesFromMetadata() 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\LinqToDB.Templates\LinqToDB.ttinclude: 行 205 於 Microsoft.VisualStudio.TextTemplating77DC7F2B06966E27F1DD4AC0DBECEEC6.GeneratedTextTransformation.<>c__DisplayClass1.<TransformText>b__0() 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\LinqToDB.Templates\DataModel.ttinclude: 行 11 於 Microsoft.VisualStudio.TextTemplating77DC7F2B06966E27F1DD4AC0DBECEEC6.GeneratedTextTransformation.GenerateModel() 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\LinqToDB.Templates\T4Model.ttinclude: 行 16 於 Microsoft.VisualStudio.TextTemplating77DC7F2B06966E27F1DD4AC0DBECEEC6.GeneratedTextTransformation.TransformText() 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\Models\CopyMe.MySql.tt: 行 42 於 Microsoft.VisualStudio.TextTemplating.TransformationRunner.RunTransformation(TemplateProcessingSession session, String source, ITextTemplatingEngineHost host, String& result) 1 1

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If I change the parameter of LoadMySqlMetadata Method like below

LoadMySqlMetadata(“localhost”, “sakila”, “root”, “mypassword”);

the error message would be different like below

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錯誤 1 正在執行轉換: System.Data.SqlTypes.SqlNullValueException: 資料為 Null。無法在值為 Null 的情況下呼叫這個方法或屬性。 於 MySql.Data.MySqlClient.MySqlDataReader.GetFieldValue(Int32 index, Boolean checkNull) 於 MySql.Data.MySqlClient.MySqlDataReader.GetString(Int32 i) 於 MySql.Data.MySqlClient.MySqlDataReader.GetString(String column) 於 MySql.Data.MySqlClient.SchemaProvider.GetIndexColumns(String[] restrictions) 於 MySql.Data.MySqlClient.SchemaProvider.GetSchemaInternal(String collection, String[] restrictions) 於 MySql.Data.MySqlClient.ISSchemaProvider.GetSchemaInternal(String collection, String[] restrictions) 於 MySql.Data.MySqlClient.SchemaProvider.GetSchema(String collection, String[] restrictions) 於 MySql.Data.MySqlClient.MySqlConnection.GetSchema(String collectionName, String[] restrictionValues) 於 MySql.Data.MySqlClient.MySqlConnection.GetSchema(String collectionName) 於 LinqToDB.DataProvider.MySql.MySqlSchemaProvider.GetPrimaryKeys(DataConnection dataConnection) 於 LinqToDB.SchemaProvider.SchemaProviderBase.GetSchema(DataConnection dataConnection, GetSchemaOptions options) 於 Microsoft.VisualStudio.TextTemplatingD168C78C55D712AF43FE7C599FEF2E64.GeneratedTextTransformation.LoadServerMetadata(DataConnection dataConnection) 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\LinqToDB.Templates\DataModel.ttinclude: 行 56 於 Microsoft.VisualStudio.TextTemplatingD168C78C55D712AF43FE7C599FEF2E64.GeneratedTextTransformation.LoadMetadata(DataConnection dataConnection) 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\LinqToDB.Templates\DataModel.ttinclude: 行 284 於 Microsoft.VisualStudio.TextTemplatingD168C78C55D712AF43FE7C599FEF2E64.GeneratedTextTransformation.LoadMySqlMetadata(String server, String database, String uid, String password) 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\LinqToDB.Templates\LinqToDB.MySql.ttinclude: 行 28 於 Microsoft.VisualStudio.TextTemplatingD168C78C55D712AF43FE7C599FEF2E64.GeneratedTextTransformation.TransformText() 於 f:\VSProj\Linq2dbDemo\Linq2dbDemo\Models\CopyMe.MySql.tt: 行 42 於 Microsoft.VisualStudio.TextTemplating.TransformationRunner.RunTransformation(TemplateProcessingSession session, String source, ITextTemplatingEngineHost host, String& result) 1 1

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[shubham6396]

Once more: you get this error during load of procedures schema due to missing information_schema.parameters view, which was added in MySQL 5.5.3. If you have lower version, you just need to disable procedures load using

GetSchemaOptions.GetProcedures = false;

If you don’t see any tables after that, it means that your schema filter is not correct (GetSchemaOptions.IncludedSchemas) - remove it and then add proper filter later if it generates tables from unwanted schemas.

Hey it worked. Thank you so much 😃

[MaceWindu]

Once more: you get this error during load of procedures schema due to missing information_schema.parameters view, which was added in MySQL 5.5.3. If you have lower version, you just need to disable procedures load using

GetSchemaOptions.GetProcedures = false;

If you don’t see any tables after that, it means that your schema filter is not correct (GetSchemaOptions.IncludedSchemas) - remove it and then add proper filter later if it generates tables from unwanted schemas.