planner: fix plus prefix for select constant

[wjhuang2016]

What problem does this PR solve?

For #9683

What is changed and how it works?

Return TRUE or FALSE for select true; or select false
Trim the plus prefix for most of types except bit literal or hex literal,
besides, trim the ( or ) and it not long needs innerExpr.Text()

Check List

Tests

• Unit test

Code changes

Side effects

Related changes

[codecov]

Codecov Report

Merging #9707 into master will decrease coverage by 0.01%.
The diff coverage is 58.3333%.

@@               Coverage Diff                @@
##             master      #9707        +/-   ##
================================================
- Coverage   67.1882%   67.1782%   -0.0101%     
================================================
  Files           381        381                
  Lines         79947      79956         +9     
================================================
- Hits          53715      53713         -2     
- Misses        21448      21455         +7     
- Partials       4784       4788         +4

[eurekaka]

@erjiaqing PTAL

[XuHuaiyu]

if i := valueExpr.GetValue().(int64); i == 0{
return xxx
}else{
return xxx
}

[wjhuang2016]

We need to check the BooleanFlag, would you mean
if mysql.HasIsBooleanFlag(valueExpr.Type.Flag) {
if i := valueExpr.GetValue().(int64); i == 0{
return xxx
}else{
return xxx
}
}

[XuHuaiyu]

Yep

[wjhuang2016]

linting
✘ https://revive.run/r#indent-error-flow if block ends with a return statement, so drop this else and outdent its block (move short variable declaration to its own line if necessary)
planner/core/logical_plan_builder.go:622:11

[XuHuaiyu]

Ok, my fault, we should not use else{

[lzmhhh123]

LGTM

[XuHuaiyu]

LGTM

[XuHuaiyu]

/run-all-tests

[wjhuang2016]

It seems that the test case in common-test need to be update.

2019/03/14 14:25:06.272 main.go:718: [fatal] run test [operator] err: sql:select --1, ++1, -+1, +1, -+!1, !-+-1;: failed to run query

"select --1, ++1, -+1, +1, -+!1, !-+-1;"

around line 13,

we need(99):

select --1, ++1, -+1, +1, -+!1, !-+-1;

--1 ++1 -+1 +1 -+!1 !-+-1

1 1 -1 18446744073709551614 0

but got(99):

select --1, ++1, -+1, +1, -+!1, !-+-1;

--1 1 -+1 +1 -+!1 !-+-1

1 1 -1 18446744073709551614 0 1

in test case, select ++1; return column name ++1

[XuHuaiyu]

/run-common-test tidb-test=pr/757
/run-integration-common-test tidb-test=pr/757

[wjhuang2016]

@XuHuaiyu Please run the test again.

[XuHuaiyu]

Check

tidb> select +
    ->
    ->   1;
+-------+
|

  1 |
+-------+
|     1 |
+-------+
1 row in set (0.00 sec)

[XuHuaiyu]

/run-all-tests

[XuHuaiyu]

/run-common-test tidb-test=pr/757
/run-integration-common-test tidb-test=pr/757

[erjiaqing]

MySQL has three white space character, [ \n\t] (in file mysql-server:storage/innobase/pars/pars0lex.l)

so, do not forget \t, this should be the last whitespace you need concern.

[wjhuang2016]

I had considered \t, but I found that I can't type \t by Mysql-client. And you're right, we need to deal with \t.