server: double type column from table should ignore its decimal (#21788…

…) (#21916) Signed-off-by: ti-srebot <ti-srebot@pingcap.com>
pingcap · Jan 26, 2021 · 6f41739 · 6f41739
1 parent 9c848a6
commit 6f41739
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Showing 3 changed files with 32 additions and 2 deletions.
diff --git a/cmd/explaintest/r/select.result b/cmd/explaintest/r/select.result
@@ -480,3 +480,18 @@ Projection_7	10000.00	root		minus(Column#5, test.t.x)->Column#7
   └─Sort_11	10000.00	root		test.t.i:asc
     └─TableReader_10	10000.00	root		data:TableRangeScan_9
       └─TableRangeScan_9	10000.00	cop[tikv]	table:t	range:[0,+inf], keep order:false, stats:pseudo
+create table precise_types (
+a BIGINT UNSIGNED NOT NULL,
+b BIGINT NOT NULL,
+c DECIMAL(21,1) NOT NULL,
+d DOUBLE(21,1) NOT NULL
+);
+insert into precise_types values (
+18446744073709551614,
+-9223372036854775806,
+99999999999999999999,
+18446744073709551614
+);
+SELECT a, b, c, d FROM precise_types;
+a	b	c	d
+18446744073709551614	-9223372036854775806	99999999999999999999.0	1.8446744073709552e19
diff --git a/cmd/explaintest/t/select.test b/cmd/explaintest/t/select.test
@@ -229,3 +229,18 @@ CREATE TABLE t (id int(10) unsigned NOT NULL AUTO_INCREMENT,
     PRIMARY KEY (`id`)
 );
 explain select row_number() over( partition by i ) - x as rnk from t;
+
+# for issue 21692
+create table precise_types (
+    a BIGINT UNSIGNED NOT NULL,
+    b BIGINT NOT NULL,
+    c DECIMAL(21,1) NOT NULL,
+    d DOUBLE(21,1) NOT NULL
+);
+insert into precise_types values (
+    18446744073709551614,
+    -9223372036854775806,
+    99999999999999999999,
+    18446744073709551614
+);
+SELECT a, b, c, d FROM precise_types;
diff --git a/server/util.go b/server/util.go
@@ -317,14 +317,14 @@ func dumpTextRow(buffer []byte, columns []*ColumnInfo, row chunk.Row) ([]byte, e
 			buffer = dumpLengthEncodedString(buffer, tmp)
 		case mysql.TypeFloat:
 			prec := -1
-			if columns[i].Decimal > 0 && int(col.Decimal) != mysql.NotFixedDec {
+			if columns[i].Decimal > 0 && int(col.Decimal) != mysql.NotFixedDec && col.Table == "" {
 				prec = int(col.Decimal)
 			}
 			tmp = appendFormatFloat(tmp[:0], float64(row.GetFloat32(i)), prec, 32)
 			buffer = dumpLengthEncodedString(buffer, tmp)
 		case mysql.TypeDouble:
 			prec := types.UnspecifiedLength
-			if col.Decimal > 0 && int(col.Decimal) != mysql.NotFixedDec {
+			if col.Decimal > 0 && int(col.Decimal) != mysql.NotFixedDec && col.Table == "" {
 				prec = int(col.Decimal)
 			}
 			tmp = appendFormatFloat(tmp[:0], row.GetFloat64(i), prec, 64)