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  1. MariaDB Server
  2. MDEV-8898

Inconsistent behaviour when comparing a YEAR column to DECIMAL or DOUBLE counterparts

        Details

        • Type: Bug
        • Status: Open
        • Priority: Major
        • Resolution: Unresolved
        • Affects Version/s: 10.1, 10.0, 5.5
        • Fix Version/s: 10.1
        • Component/s: None
        • Labels:
          None

          Description

          Comparison of a YEAR column to DECIMAL and DOUBLE literal works differently in different function and operators:

          DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (a YEAR);
INSERT INTO t1 VALUES (2000);
SELECT a=2000.1 AS c1, CASE a WHEN 2000.1 THEN TRUE ELSE FALSE END AS c2, NULLIF(a,2000.1) AS c3, GREATEST(a,2000.1) AS c4 FROM t1;

          returns:

          +------+------+------+--------+
| c1   | c2   | c3   | c4     |
+------+------+------+--------+
|    1 |    0 | NULL | 2000.1 |
+------+------+------+--------+

          That means:

          • for c1 it compared as YEAR
          • for c2 it compared as DECIMAL
          • for c3 it compared as YEAR
          • for c4 it compared as DECIMAL

          It should work the same way in all functions. Perhaps it should always compare as follows:

          • YEAR vs DECIMAL as DECIMAL
          • YEAR vs DOUBLE as DOUBLE

          Another option would be to compare:

          • YEAR vs DECIMAL as YEAR
          • YEAR vs DOUBLE as YEAR

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                  • Assignee:
                    bar Alexander Barkov
                    Reporter:
                    bar Alexander Barkov
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                    Dates

                    • Created:
                      Updated: