pingcap/tidb

Error 1054: Unknown column 'a' in 'field list'

Open

#8,190 opened on Nov 6, 2018

View on GitHub
 (5 comments) (0 reactions) (1 assignee)Go (40,090 stars) (6,186 forks)batch import
challenge-programhelp wantedseverity/moderatesig/plannertype/bug

Description

Description

Bug Report

Please answer these questions before submitting your issue. Thanks!

  1. What did you do?
select 1 as a,(select a union select a);
  1. What did you expect to see?
mysql> select 1 as a,(select a union select a);
+---+---------------------------+
| a | (select a union select a) |
+---+---------------------------+
| 1 |                         1 |
+---+---------------------------+
1 row in set (0.00 sec)
  1. What did you see instead?
tidb> select 1 as a,(select a union select a);
ERROR 1054 (42S22): Unknown column 'a' in 'field list'
  1. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?
tidb> select tidb_version();                                                        +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                                                                     |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v2.1.0-rc.3-147-g379ee5b19
Git Commit Hash: 379ee5b1915a37d14e45230acf4d911c6b80d07d
Git Branch: master
UTC Build Time: 2018-11-06 03:12:11
GoVersion: go version go1.11 darwin/amd64
Race Enabled: false
TiKV Min Version: 2.1.0-alpha.1-ff3dd160846b7d1aed9079c389fc188f7f5ea13e
Check Table Before Drop: false |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

SIG slack channel

#sig-exec

Score

300

Mentor

  • @lzmhhh123

Contributor guide

Tech stack
gosql
Domain
backenddatabase
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
SQL subqueriesTiDB execution engine basicsGo programming language
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
Investigate how TiDB resolves columns in subqueries within SELECT clauses. Look at the expression evaluator and planner code, particularly around column resolution for correlated subqueries. Check if the issue is in the planner building the wrong plan or the executor failing to find the column. The mentor @lzmhhh123 can provide guidance on relevant files.