Bug #93994 Parameter marker aliases in inner SELECTs are not propagated to outer SELECTs

• Submitted: 21 Jan 2019 15:08
• Modified: 7 Feb 2019 14:25
• Reporter: GC GC
• Status: Closed
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 5.6.17
• OS: Any
• CPU Architecture: Any

[21 Jan 2019 15:08] GC GC

Description:
A call to SQLPrepare with:
const char *sql = "SELECT X, Y FROM (SELECT 1 X, ? AS Y) Q";
fails with "[MySQL][ODBC 5.3(a) Driver][mysqld-5.6.17] Unknown column 'Y' in 'field list'"

Workaround (replace single parameter with 2 inside a COALESCE):
const char *sql = "SELECT X, Y FROM (SELECT 1 X, COALESCE(?, ?) Y) Q";

Also works: sql without the outer select

Also fails (with "Unknown column 'Q.Y' in 'field list'"): 
const char *sql = "SELECT Q.X, Q.Y FROM (SELECT 1 X, ? Y) Q";

So the bug seems to be that parameter marker aliases in inner SELECTs are not propagated to the outer SELECTs.

How to repeat:
Execute the aforementioned SQL statement using a MySQL ODBC driver.

[24 Jan 2019 19:50] GC GC

Discovered that the bug does not occur against a MySQL server version 5.6.40.

[7 Feb 2019 14:25] MySQL Verification Team

Thank you for the feedback. Closed according your last comment.