executor,expression: avoid to append nil to warnings

executor/insert.go

@@ -199,7 +199,7 @@ func (e *InsertExec) updateDupRow(ctx context.Context, idxInBatch int, txn kv.Tr
 		extraCols = e.ctx.GetSessionVars().CurrInsertBatchExtraCols[idxInBatch]
 	}
 
-	err = e.doDupRowUpdate(ctx, handle, oldRow, row.row, extraCols, e.OnDuplicate)
+	err = e.doDupRowUpdate(ctx, handle, oldRow, row.row, extraCols, e.OnDuplicate, idxInBatch)
 	if e.ctx.GetSessionVars().StmtCtx.DupKeyAsWarning && kv.ErrKeyExists.Equal(err) {
 		e.ctx.GetSessionVars().StmtCtx.AppendWarning(err)
 		return nil
@@ -374,7 +374,7 @@ func (e *InsertExec) initEvalBuffer4Dup() {
 
 // doDupRowUpdate updates the duplicate row.
 func (e *InsertExec) doDupRowUpdate(ctx context.Context, handle kv.Handle, oldRow []types.Datum, newRow []types.Datum,
-	extraCols []types.Datum, cols []*expression.Assignment) error {
+	extraCols []types.Datum, cols []*expression.Assignment, idxInBatch int) error {
 	assignFlag := make([]bool, len(e.Table.WritableCols()))
 	// See http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 	e.curInsertVals.SetDatums(newRow...)
@@ -390,6 +390,8 @@ func (e *InsertExec) doDupRowUpdate(ctx context.Context, handle kv.Handle, oldRo
 
 	// Update old row when the key is duplicated.
 	e.evalBuffer4Dup.SetDatums(e.row4Update...)
+	sc := e.ctx.GetSessionVars().StmtCtx
+	warnCnt := int(sc.WarningCount())
 	for _, col := range cols {
 		if col.LazyErr != nil {
 			return col.LazyErr
@@ -398,10 +400,20 @@ func (e *InsertExec) doDupRowUpdate(ctx context.Context, handle kv.Handle, oldRo
 		if err1 != nil {
 			return err1
 		}
-		e.row4Update[col.Col.Index], err1 = table.CastValue(e.ctx, val, col.Col.ToInfo(), false, false)
+		c := col.Col.ToInfo()
+		c.Name = col.ColName
+		e.row4Update[col.Col.Index], err1 = table.CastValue(e.ctx, val, c, false, false)
 		if err1 != nil {
 			return err1
 		}
+		if newWarnings := sc.TruncateWarnings(warnCnt); len(newWarnings) > 0 {
+			for k := range newWarnings {
+				// Use `idxInBatch` here for simplicity, since the offset of the batch is unknown under the current context.
+				newWarnings[k].Err = completeInsertErr(c, &val, idxInBatch, newWarnings[k].Err)
+			}
+			sc.AppendWarnings(newWarnings)
+			warnCnt += len(newWarnings)
+		}
 		e.evalBuffer4Dup.SetDatum(col.Col.Index, e.row4Update[col.Col.Index])
 		assignFlag[col.Col.Index] = true
 	}

executor/insert_common.go

@@ -287,12 +287,7 @@ func insertRows(ctx context.Context, base insertCommon) (err error) {
 	return nil
 }
 
-func (e *InsertValues) handleErr(col *table.Column, val *types.Datum, rowIdx int, err error) error {
-	if err == nil {
-		return nil
-	}
-
-	// Convert the error with full messages.
+func completeInsertErr(col *model.ColumnInfo, val *types.Datum, rowIdx int, err error) error {
 	var (
 		colTp   byte
 		colName string
@@ -323,6 +318,20 @@ func (e *InsertValues) handleErr(col *table.Column, val *types.Datum, rowIdx int
 	} else if types.ErrWarnDataOutOfRange.Equal(err) {
 		err = types.ErrWarnDataOutOfRange.GenWithStackByArgs(colName, rowIdx+1)
 	}
+	return err
+}
+
+func (e *InsertValues) handleErr(col *table.Column, val *types.Datum, rowIdx int, err error) error {
+	if err == nil {
+		return nil
+	}
+
+	// Convert the error with full messages.
+	var c *model.ColumnInfo
+	if col != nil {
+		c = col.ColumnInfo
+	}
+	err = completeInsertErr(c, val, rowIdx, err)
 
 	if !e.ctx.GetSessionVars().StmtCtx.DupKeyAsWarning {
 		return err
@@ -350,6 +359,8 @@ func (e *InsertValues) evalRow(ctx context.Context, list []expression.Expression
 	}
 
 	e.evalBuffer.SetDatums(row...)
+	sc := e.ctx.GetSessionVars().StmtCtx
+	warnCnt := int(sc.WarningCount())
 	for i, expr := range list {
 		val, err := expr.Eval(e.evalBuffer.ToRow())
 		if err != nil {
@@ -359,6 +370,13 @@ func (e *InsertValues) evalRow(ctx context.Context, list []expression.Expression
 		if err = e.handleErr(e.insertColumns[i], &val, rowIdx, err); err != nil {
 			return nil, err
 		}
+		if newWarnings := sc.TruncateWarnings(warnCnt); len(newWarnings) > 0 {
+			for k := range newWarnings {
+				newWarnings[k].Err = completeInsertErr(e.insertColumns[i].ColumnInfo, &val, rowIdx, newWarnings[k].Err)
+			}
+			sc.AppendWarnings(newWarnings)
+			warnCnt += len(newWarnings)
+		}
 
 		offset := e.insertColumns[i].Offset
 		val1.Copy(&row[offset])
@@ -378,6 +396,8 @@ func (e *InsertValues) fastEvalRow(ctx context.Context, list []expression.Expres
 	}
 	row := make([]types.Datum, rowLen)
 	hasValue := make([]bool, rowLen)
+	sc := e.ctx.GetSessionVars().StmtCtx
+	warnCnt := int(sc.WarningCount())
 	for i, expr := range list {
 		con := expr.(*expression.Constant)
 		val, err := con.Eval(emptyRow)
@@ -388,6 +408,13 @@ func (e *InsertValues) fastEvalRow(ctx context.Context, list []expression.Expres
 		if err = e.handleErr(e.insertColumns[i], &val, rowIdx, err); err != nil {
 			return nil, err
 		}
+		if newWarnings := sc.TruncateWarnings(warnCnt); len(newWarnings) > 0 {
+			for k := range newWarnings {
+				newWarnings[k].Err = completeInsertErr(e.insertColumns[i].ColumnInfo, &val, rowIdx, newWarnings[k].Err)
+			}
+			sc.AppendWarnings(newWarnings)
+			warnCnt += len(newWarnings)
+		}
 		offset := e.insertColumns[i].Offset
 		row[offset], hasValue[offset] = val1, true
 	}

expression/integration_test.go

@@ -7469,6 +7469,28 @@ func TestIssue31600(t *testing.T) {
 	tk.MustExec("drop table t")
 }
 
+func TestIssue31569(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+
+	tk := testkit.NewTestKit(t, store)
+
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t (c int primary key, c2 enum('a', 'b'))")
+	tk.MustExec("set session sql_mode = ''")
+	tk.MustExec("insert into t values(4, 'a')")
+	tk.MustExec("insert into t values(4, 0) on duplicate key update c=values(c), c2=values(c2)")
+	// tidb produces two warnings here (when eval (4, 0) & values(c2)), which is slightly incompatible with mysql
+	tk.MustQuery("show warnings").Check([][]interface{}{
+		{"Warning", "1265", "Data truncated for column 'c2' at row 1"},
+		{"Warning", "1265", "Data truncated for column 'c2' at row 1"},
+	})
+	tk.MustExec("insert into t values(4, 'a') on duplicate key update c=values(c), c2=values(c2)")
+	tk.MustQuery("show warnings").Check([][]interface{}{})
+	tk.MustExec("drop table t")
+}
+
 func TestDateAddForNonExistingTimestamp(t *testing.T) {
 	store, clean := testkit.CreateMockStore(t)
 	defer clean()

expression/scalar_function.go

@@ -375,10 +375,7 @@ func (sf *ScalarFunction) Eval(row chunk.Row) (d types.Datum, err error) {
 			res, err = types.ParseEnum(tp.GetElems(), str, tp.GetCollate())
 			if ctx := sf.GetCtx(); ctx != nil {
 				if sc := ctx.GetSessionVars().StmtCtx; sc != nil {
-					if sc.TruncateAsWarning {
-						ctx.GetSessionVars().StmtCtx.AppendWarning(err)
-						err = nil
-					}
+					err = sc.HandleTruncate(err)
 				}
 			}
 		} else {