CASE When: result type should be coercible to a common type #2818
Description
Describe the bug
❯ select case when 1=1 then true else 1 end;
+--------------------------------------------------------------------+
| CASE WHEN Int64(1) = Int64(1) THEN Boolean(true) ELSE Int64(1) END |
+--------------------------------------------------------------------+
| true |
+--------------------------------------------------------------------+
1 row in set. Query took 0.042 seconds.
❯ explain select case when 1=1 then true else 1 end;
+---------------+---------------------------------------------------------------------------------------------------+
| plan_type | plan |
+---------------+---------------------------------------------------------------------------------------------------+
| logical_plan | Projection: Boolean(true) AS CASE WHEN Int64(1) = Int64(1) THEN Boolean(true) ELSE Int64(1) END |
| | EmptyRelation |
| physical_plan | ProjectionExec: expr=[true as CASE WHEN Int64(1) = Int64(1) THEN Boolean(true) ELSE Int64(1) END] |
| | EmptyExec: produce_one_row=true |
| | |
+---------------+---------------------------------------------------------------------------------------------------+
2 rows in set. Query took 0.003 seconds.
❯ explain select case when 1>1 then true else 1 end;
+---------------+---------------------------------------------------------------------------------------------------+
| plan_type | plan |
+---------------+---------------------------------------------------------------------------------------------------+
| logical_plan | Projection: Boolean(true) AS CASE WHEN Int64(1) > Int64(1) THEN Boolean(true) ELSE Int64(1) END |
| | EmptyRelation |
| physical_plan | ProjectionExec: expr=[true as CASE WHEN Int64(1) > Int64(1) THEN Boolean(true) ELSE Int64(1) END] |
| | EmptyExec: produce_one_row=true |
| | |
+---------------+---------------------------------------------------------------------------------------------------+
2 rows in set. Query took 0.004 seconds.
❯ select case when 1>1 then true else 1 end;
+--------------------------------------------------------------------+
| CASE WHEN Int64(1) > Int64(1) THEN Boolean(true) ELSE Int64(1) END |
+--------------------------------------------------------------------+
| true |
+--------------------------------------------------------------------+
One case when sql has two diff result data type.
From other system, case when should have the common data type, but now the result type is the first non-null data type.
To Reproduce
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Expected behavior
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Additional context
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