Runtime System.Exception when ContextSchemaPath is defined

先从 ContextSchemaPath 的行为和堆栈跟踪条目 FSharp.Data.Sql.Providers.MySql.findClrType@91-1 开始，然后按照列出的步骤重现数据库操作。当缓存的架构支持设计时和编译时使用，且不会在运行时数据库操作期间加载，从而使插入不再引发 System.Exception: ! 时，即表示完成。

Description

When the ContextSchemaPath locally cached schema file is defined and present, SQLProvider returns System.Exception: ! when performing database operations at runtime.

Repro steps

1. Generate a local schema file with ContextSchemaPath as described in the documentation

2. Debug the project

3. Perform a database operation. The following exception is raised:

System.Exception: !
   at FSharp.Data.Sql.Providers.MySql.findClrType@91-1.Invoke(String _arg1)
   at FSharp.Data.Sql.Providers.MySql.createParam[a](String name, Int32 i, a v)
   at <StartupCode$FSharp-Data-SqlProvider>.$Providers.MySql.clo@350-280.Invoke(Tuple`2 tupledArg)
   at Microsoft.FSharp.Collections.SeqModule.Fold[T,TState](FSharpFunc`2 folder, TState state, IEnumerable`1 source)
   at FSharp.Data.Sql.Providers.MySqlProvider.createInsertCommand(IDbConnection con, StringBuilder sb, SqlEntity entity)
   at <StartupCode$FSharp-Data-SqlProvider>.$Providers.MySql.FSharp-Data-Sql-Common-ISqlProvider-ProcessUpdates@949-3.Invoke(SqlEntity e)
   at Microsoft.FSharp.Collections.SeqModule.Iterate[T](FSharpFunc`2 action, IEnumerable`1 source)
   at FSharp.Data.Sql.Providers.MySqlProvider.FSharp-Data-Sql-Common-ISqlProvider-ProcessUpdates(IDbConnection con, ConcurrentDictionary`2 entities, TransactionOptions transactionOptions, FSharpOption`1 timeout)
   at <StartupCode$FSharp-Data-SqlProvider>.$SqlRuntime.DataContext.f@1-69(SqlDataContext __, IDbConnection con, Unit unitVar0)
   at FSharp.Data.Sql.Runtime.SqlDataContext.FSharp-Data-Sql-Common-ISqlDataContext-SubmitPendingChanges()
   at MyProject.DoDatabaseStuff(DbRow _row) in C:\Users\Me\Code\MyProject\Db.fs:line 65
Stopped due to error

Expected behavior

The type provider should not attempt to load the ContextSchemaPath at runtime since it is not a data source and will never work. It should only load at design-time and compile-time to allow development and compilation (build server) without a full-time database connection.

Known workarounds

Workarounds are to either not use the ContextSchemaPath at all, or delete the cached schema file each time debugging is needed.

Related information

• Used database: MySQL 5.6
• Operating system Window 10 version 1803
• Branch: 1.1.42
• .NET Runtime: 4.5.2
• Performance information, links to performance testing scripts : N/A