statistics: fix a error check to prevent nil dereference (#27295) (#2…

…7305)
pingcap · Sep 10, 2021 · 50b4763 · 50b4763
1 parent 540493b
commit 50b4763
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/statistics/selectivity.go b/statistics/selectivity.go
@@ -305,10 +305,10 @@ func getMaskAndRanges(ctx sessionctx.Context, exprs []expression.Expression, ran
 		}
 		var res *ranger.DetachRangeResult
 		res, err = ranger.DetachCondAndBuildRangeForIndex(ctx, exprs, cols, lengths)
-		ranges, accessConds, remainedConds, isDNF = res.Ranges, res.AccessConds, res.RemainedConds, res.IsDNFCond
 		if err != nil {
 			return 0, nil, false, err
 		}
+		ranges, accessConds, remainedConds, isDNF = res.Ranges, res.AccessConds, res.RemainedConds, res.IsDNFCond
 	default:
 		panic("should never be here")
 	}

diff --git a/statistics/selectivity_test.go b/statistics/selectivity_test.go
@@ -667,3 +667,13 @@ func (s *testStatsSuite) TestCollationColumnEstimate(c *C) {
 		tk.MustQuery(input[i]).Check(testkit.Rows(output[i]...))
 	}
 }
+
+func (s *testStatsSuite) TestIssue27294(c *C) {
+	defer cleanEnv(c, s.store, s.do)
+	testKit := testkit.NewTestKit(c, s.store)
+
+	testKit.MustExec("use test")
+	testKit.MustExec("drop table if exists tt")
+	testKit.MustExec("create table tt (COL1 blob DEFAULT NULL,COL2 decimal(37,4) DEFAULT NULL,COL3 timestamp NULL DEFAULT NULL,COL4 int(11) DEFAULT NULL,UNIQUE KEY U_M_COL4(COL1(10),COL2), UNIQUE KEY U_M_COL5(COL3,COL2));")
+	testKit.MustExec("explain select * from tt where col1 is not null or col2 not between 454623814170074.2771 and -975540642273402.9269 and col3 not between '2039-1-19 10:14:57' and '2002-3-27 14:40:23';")
+}