executor: fix update join result when join table order changed

[lysu]

What problem does this PR solve?

this question is introduced by #7177

create two simple table and one of them have primary key.

create table t6 (id int, v longtext);
create table t7 (x int, id int, v longtext, primary key(id);
insert into t6 values (1, NULL);
insert into t7 values (5, 1, 'a')

execute this

update t6, t7 set t6.v = t7.v where t6.id = t7.id

will make t6.v be a.

but with

update t6, t7 set t6.v = t7.v where t6.id = t7.id and t7.x = 5;

will update nothing.

because added t7.x = 5 will change plan from t6 join t7 to t7 join t6 and in update there are no projection stage like select stmt.

one of new added code doesn't take care about it and use updateExec.schema to build handle identity map, but use update.selectExec.schema to query map, so meet error.

What is changed and how it works?

build identity map using update.SelectPlan instead of updatePlan, oneline change.

Check List

Tests

• Unit test
• Integration test

Code changes

• bug fix

Side effects

• no

Related changes

• no

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This change is 

[lysu]

/run-all-tests

[zz-jason]

LGTM

[eurekaka]

LGTM

[winoros]

lgtm