sqlc >= v1.18.0 detects a string concatenation as `sql.NullBool`

[jamietanna]

Version

1.21.0

What happened?

I've just done a few version bumps up to v1.21.0 and noticed that:

select
-- ...
db.engine || ' ' || db.engine_version as runtime

Ends up being converted to an sql.NullBool.

The upgrade diff for the generate structs can be found below:

 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.17.0
+//   sqlc v1.21.0
 // source: queries.sql
 
 package db
@@ -198,21 +198,11 @@ where
 `
 
 type RetrieveAWSAdvisoriesRow struct {
-       Arn            string
-       Name           string
-       Runtime        interface{}
-       AdvisoryType   interface{}
-       Description    interface{}
-       Arn_2          string
-       Name_2         string
-       Runtime_2      string
-       AdvisoryType_2 interface{}
-       Description_2  interface{}
-       Arn_3          string
-       Name_3         string
-       Runtime_3      interface{}
-       AdvisoryType_3 interface{}
-       Description_3  interface{}
+       Arn          string
+       Name         string
+       Runtime      sql.NullBool
+       AdvisoryType interface{}
+       Description  interface{}
 }

Previously it was an interface{} or a string, whereas now it's a sql.NullBool 🤔

I've had a look back on the Playground as far back as v1.18.0 (link) and it affects that as well as up to v1.21.0 (with #2729 applied locally)

Relevant log output

No response

Database schema

No response

SQL queries

No response

Configuration

No response

Playground URL

https://play.sqlc.dev/p/4644276ab2d6a08adc69359a99b241c23a0ce108f0a01d9bb937a81d584501ef

What operating system are you using?

Linux

What database engines are you using?

SQLite

What type of code are you generating?

Go

[jamietanna]

It looks like a workaround can be to use:

  printf('%s %s', db.engine , db.engine_version) as r,

Which then outputs:

	R       sql.NullString

[jamietanna]

Any idea why it may be presenting a NullString instead of just a string?

[orisano]

In SQLite it is mistaken for a bool, but in PostgreSQL and MySQL it is also an interface{}.

[orisano]

Two problems are causing this issue.

• sqlite is treating "||" as equivalent to "OR".
• The compiler is treating the result of the "||" operator as any.