Add TreatTinyAsBoolean connection string option

[bgrainger]

Implement the TreatTinyAsBoolean connection string option:

• false - TINYINT(1) is a byte/sbyte
• true (default) - TINYINT(1) is a bool

[caleblloyd]

I am about to start work on this, but I think it is worth discussing if TreatTinyAsBoolean=true is a sensible default. In my opinion, changing the data types based off length is unpredictable and therefore is not a sensible default, I would prefer to use TreatTinyAsBoolean=false as the default

I can see how it is confusing if somebody was using BOOL or BOOLEAN as their field types, however. MySql has created an alias of BOOL and BOOLEAN to map to TINYINT(1) (they should have made the alias map to BIT(1), but too late for that). In this case, I understand why somebody would expect TreatTinyAsBoolean=true as the default.

@bgrainger what is your opinion?

[bgrainger]

Since MySQL doesn't support BOOL (but just aliases BOOL to TINYINT(1)), any .NET developer would be highly surprised if BOOL columns didn't map to bool by default. We should match Connector/Net here and keep true as the default.

I'm unsure of the value of supporting setting this option to false; when would a TINYINT(1) column be created explicitly in a table schema? The default for TINYINT is TINYINT(3). (Maybe if someone thinks (1) is the number of bytes, not the number of decimal digits to use when formatting the column by default?)

OTOH, if implementing this isn't a huge pain, then no real objections to adding the option; people may be using it in the wild.

[bgrainger]

It's not popular, but it is used.

[caleblloyd]

I'm unsure of the value of supporting setting this option to false; when would a TINYINT(1) column be created explicitly in a table schema?

Sometimes I see TINYINT(1) used as a small status field, like 0=invited, 1=activated, 2=deactivated. Lots of times I see it used as a boolean. But you're right, the number really only applies to zerofill even though there's a common misconception that it represents the number of bytes.

I'll implement it with true as the default.

[bgrainger]

Shipped in 0.9.0.

[AccessViolator]

@bgrainger
Strangely enough I can't read TINYINT(1) as bool with default setting with Pomelo: link. I closed that issue, as there's a workaround, but it still feels like a bug, though most likely Pomelo's. What do you think?

[bgrainger]

@AccessViolator I don't know enough about Pomelo and EF.Core to comment, but I would naively expect System.Boolean in .NET to be mapped to/from TINYINT(1) (aka BOOL) in MySQL.

[caleblloyd]

It is mapped to bit(1): https://github.com/PomeloFoundation/Pomelo.EntityFrameworkCore.MySql/blob/4c099402e3c044fe0cc0d876d8e73630f2eb36c6/src/EFCore.MySql/Storage/Internal/MySqlBoolTypeMapping.cs#L29

[a-patel]

@bgrainger
Any update, I am facing a similar issue using ADO.NET.

[bgrainger]

@a-patel This issue is for tracking the implementation of the connection string option, which is done. If you have a bug report or question, please open a new issue.