Gracefully handle divide by zero (#2306)

Divide by zero in SQL expressions will be reported as SQL errors.

sql3/errors.go

@@ -139,6 +139,9 @@ const (
 	ErrQRangeFromAndToTimeCannotBeBothNull errors.Code = "ErrQRangeFromAndToTimeCannotBeBothNull"
 	ErrQRangeInvalidUse                    errors.Code = "ErrQRangeInvalidUse"
 	ErrYearOutOfRange                      errors.Code = "ErrYearOutOfRange"
+
+	//evaluate errors
+	ErrDivideByZero errors.Code = "ErrDivideByZero"
 )
 
 func NewErrDuplicateColumn(line int, col int, column string) error {
@@ -860,3 +863,10 @@ func NewErrYearOutOfRange(line, col int, year int) error {
 		fmt.Sprintf("[%d:%d] year '%d' out of range [0,9999]", line, col, year),
 	)
 }
+
+func NewErrDivideByZero(line, col int) error {
+	return errors.New(
+		ErrDivideByZero,
+		fmt.Sprintf("[%d:%d] divisor is equal to zero", line, col),
+	)
+}

sql3/planner/expression.go

@@ -419,11 +419,15 @@ func (n *binOpPlanExpression) Evaluate(currentRow []interface{}) (interface{}, e
 			case parser.STAR:
 				return nl * nr, nil
 			case parser.SLASH:
+				if nr == 0 {
+					return nil, sql3.NewErrDivideByZero(0, 0)
+				}
 				return nl / nr, nil
-
 			case parser.REM:
+				if nr == 0 {
+					return nil, sql3.NewErrDivideByZero(0, 0)
+				}
 				return nl % nr, nil
-
 			default:
 				return nil, sql3.NewErrInternalf("unhandled operator %d", n.op)
 			}
@@ -2747,10 +2751,16 @@ func (p *ExecutionPlanner) compileBinaryExpr(expr *parser.BinaryExpr) (_ types.P
 				return newIntLiteralPlanExpression(value), nil
 
 			case parser.SLASH:
+				if numy == 0 {
+					return nil, sql3.NewErrDivideByZero(expr.OpPos.Line, expr.OpPos.Column)
+				}
 				value := numx / numy
 				return newIntLiteralPlanExpression(value), nil
 
 			case parser.REM:
+				if numy == 0 {
+					return nil, sql3.NewErrDivideByZero(expr.OpPos.Line, expr.OpPos.Column)
+				}
 				value := numx % numy
 				return newIntLiteralPlanExpression(value), nil
 

sql3/test/defs/defs_binops.go

@@ -20,6 +20,34 @@ var binOpExprWithIntInt = TableTest{
 		),
 	),
 	SQLTests: []SQLTest{
+		{
+			name: "DivisionDivideByZeroLiteral",
+			SQLs: sqls(
+				"select 1/0",
+			),
+			ExpErr: "divisor is equal to zero",
+		},
+		{
+			name: "DivisionDivideByZeroRow",
+			SQLs: sqls(
+				"select a/0 from binoptesti_i;",
+			),
+			ExpErr: "divisor is equal to zero",
+		},
+		{
+			name: "ModuloDivideByZeroLiteral",
+			SQLs: sqls(
+				"select 1%0",
+			),
+			ExpErr: "divisor is equal to zero",
+		},
+		{
+			name: "ModuloDivideByZeroRow",
+			SQLs: sqls(
+				"select a%0 from binoptesti_i;",
+			),
+			ExpErr: "divisor is equal to zero",
+		},
 		{
 			SQLs: sqls(
 				"select a != b from binoptesti_i;",