panic when insert values with a valid column plus somethings

[winkyao]

MySQL:

mysql> create table t1 (a int not null);
Query OK, 0 rows affected (0.01 sec)

mysql> insert into t1 values (a+2);
Query OK, 1 row affected (0.00 sec)

mysql> select * from t1;
+---+
| a |
+---+
| 2 |
+---+
1 row in set (0.00 sec)

TiDB:

mysql> create table t1 (a int not null);
Query OK, 0 rows affected (0.07 sec)

mysql> insert into t1 values (a+2);
ERROR 2013 (HY000): Lost connection to MySQL server during query

panic with logs:

2017/09/08 23:30:25.637 conn.go:387: [error] lastCmd insert into t1 values (a+2), runtime error: invalid memory address or nil pointer dereference, goroutine 593 [running]:
github.com/pingcap/tidb/server.(*clientConn).Run.func1(0xc42026f3f0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/server/conn.go:385 +0xcd
panic(0x109aca0, 0x1cba290)
  /usr/local/go/src/runtime/panic.go:489 +0x2cf
github.com/pingcap/tidb/expression.(*Schema).FindColumnAndIndex(0x0, 0xc42081b2d0, 0x0, 0xc420246c00, 0xc4208f9800, 0x0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/expression/schema.go:111 +0x7b
github.com/pingcap/tidb/expression.(*Schema).FindColumn(0x0, 0xc42081b2d0, 0x0, 0x450bf7, 0xc4209d3320)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/expression/schema.go:102 +0x35
github.com/pingcap/tidb/plan.(*expressionRewriter).toColumn(0xc42081b3b0, 0xc42081b2d0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/plan/expression_rewriter.go:1120 +0x51
github.com/pingcap/tidb/plan.(*expressionRewriter).Leave(0xc42081b3b0, 0x1994660, 0xc42081b2d0, 0x1994660, 0xc42081b2d0, 0xc420850f00)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/plan/expression_rewriter.go:694 +0xa68
github.com/pingcap/tidb/ast.(*ColumnName).Accept(0xc42081b2d0, 0x198cba0, 0xc42081b3b0, 0x19946a0, 0xc4207b5500, 0x0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/ast/expressions.go:345 +0x9c
github.com/pingcap/tidb/ast.(*ColumnNameExpr).Accept(0xc4207b5500, 0x198cba0, 0xc42081b3b0, 0x1994520, 0xc4207e0820, 0x0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/ast/expressions.go:367 +0xa8
github.com/pingcap/tidb/ast.(*BinaryOperationExpr).Accept(0xc4207e0820, 0x198cba0, 0xc42081b3b0, 0x10, 0x1169800, 0xc4208a9898)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/ast/expressions.go:151 +0xb0
github.com/pingcap/tidb/plan.(*planBuilder).rewriteWithPreprocess(0xc4207b55c0, 0x199e660, 0xc4207e0820, 0x0, 0x0, 0x0, 0x1, 0x0, 0xc420851501, 0xc4207b1950, ...)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/plan/expression_rewriter.go:84 +0x120
github.com/pingcap/tidb/plan.(*planBuilder).rewrite(0xc4207b55c0, 0x199e660, 0xc4207e0820, 0x0, 0x0, 0x0, 0x1, 0x1, 0xc4207b18c0, 0x1, ...)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/plan/expression_rewriter.go:65 +0x88
github.com/pingcap/tidb/plan.(*planBuilder).buildInsert(0xc4207b55c0, 0xc420774960, 0x500d82e1, 0xc4208275f0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/plan/planbuilder.go:746 +0xbfb
github.com/pingcap/tidb/plan.(*planBuilder).build(0xc4207b55c0, 0x1994ea0, 0xc420774960, 0x0, 0xc4208275f0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/plan/planbuilder.go:150 +0x2e9
github.com/pingcap/tidb/plan.Optimize(0x199f240, 0xc42026f600, 0x1994ea0, 0xc420774960, 0x7f960889bcb8, 0xc4209e3020, 0x0, 0x0, 0x1cd0020, 0x7f96088ea000)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/plan/optimizer.go:71 +0x1a7
github.com/pingcap/tidb/executor.(*Compiler).Compile(0xc4208518f0, 0x199f240, 0xc42026f600, 0x7f960889c2a0, 0xc420774960, 0xc4208518f0, 0x4867d2, 0xc420697500, 0xc4207e7db0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/executor/compiler.go:41 +0x1b7
github.com/pingcap/tidb.Compile(0x199f240, 0xc42026f600, 0x7f960889c2a0, 0xc420774960, 0x4, 0x121f7e8, 0xf, 0xc4200128c0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/tidb.go:150 +0x57
github.com/pingcap/tidb.(*session).Execute(0xc42026f600, 0xc420816201, 0x1b, 0xc420851bb8, 0x410aac, 0xc420851bb8, 0x411082, 0xc420642040)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/session.go:667 +0x518
github.com/pingcap/tidb/server.(*TiDBContext).Execute(0xc420276390, 0xc420816201, 0x1b, 0x0, 0x0, 0xc420851c88, 0x470658, 0xc4206888f8)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/server/driver_tidb.go:194 +0x62
github.com/pingcap/tidb/server.(*clientConn).handleQuery(0xc42026f3f0, 0xc420816201, 0x1b, 0x0, 0x0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/server/conn.go:727 +0x8d
github.com/pingcap/tidb/server.(*clientConn).dispatch(0xc42026f3f0, 0xc420816201, 0x1c, 0x1b, 0x0, 0x0)
  /home/wink/machome/go_dir/src/github.com/pingcap/tidb/server/conn.go:516 +0x42e

[winoros]

It seems that mysql treat the column in values() as NULL value. So we do a expression rewrite in executor build phase?

mysql> create table t(a int);
Query OK, 0 rows affected (0.00 sec)

mysql> insert into t values(a);
Query OK, 1 row affected (0.01 sec)

mysql> select * from t;
+------+
| a    |
+------+
| NULL |
+------+
1 row in set (0.00 sec)

mysql> create table t(a enum('a', 'b'));
Query OK, 0 rows affected (0.01 sec)

mysql> insert into t values(a);
Query OK, 1 row affected (0.00 sec)

mysql> select * from t;
+------+
| a    |
+------+
| NULL |
+------+
1 row in set (0.00 sec)

mysql> create table t(a blob);
Query OK, 0 rows affected (0.01 sec)

mysql> insert into t values(a);
Query OK, 1 row affected (0.00 sec)

mysql> select * from t;
+------+
| a    |
+------+
| NULL |
+------+
1 row in set (0.00 sec)

mysql> create table t(a int, b int);
Query OK, 0 rows affected (0.00 sec)

mysql> insert into t values(a*b, b*b);
Query OK, 1 row affected (0.00 sec)

mysql> select * from t;
+------+------+
| a    | b    |
+------+------+
| NULL | NULL |
+------+------+
1 row in set (0.00 sec)

[winkyao]

@winoros if the column has not null flag, MySQL will treat it as zero value:

mysql> create table t1 (a int not null);
Query OK, 0 rows affected (0.01 sec)

mysql> insert into t1 values(a);
Query OK, 1 row affected (0.01 sec)

mysql> select * from t1;
+---+
| a |
+---+
| 0 |
+---+
1 row in set (0.00 sec)

[XuHuaiyu]

In MySQL:

drop table if exists t;
create table t (a bigint not null, b bigint not null);
insert into t value(b + 1, a);
insert into t set a = b + a, b = a + 1;
insert into t value(sysdate(), a);
select * from t;

+----------------+----------------+
| a              | b              |
+----------------+----------------+
|              1 |              1 |
|              0 |              1 |
| 20170913183817 | 20170913183817 |
+----------------+----------------+
3 rows in set (0.00 sec)