// valueToBigRat converts a numeric 'value' into a big.Rat object.
func valueToBigRat(value sqltypes.Value) (*big.Rat, error) {
	switch {
	case value.IsUnsigned():
		nativeValue, err := value.ParseUint64()
		if err != nil {
			return nil, err
		}
		return uint64ToBigRat(nativeValue), nil
	case value.IsSigned():
		nativeValue, err := value.ParseInt64()
		if err != nil {
			return nil, err
		}
		return int64ToBigRat(nativeValue), nil
	case value.IsFloat():
		nativeValue, err := value.ParseFloat64()
		if err != nil {
			return nil, err
		}
		return float64ToBigRat(nativeValue), nil
	default:
		panic(fmt.Sprintf("got value with a non numeric type: %v", value))
	}
}
Beispiel #2
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// getWhereClause returns a whereClause based on desired upper and lower
// bounds for primary key.
func (qs *QuerySplitter) getWhereClause(whereClause *sqlparser.Where, bindVars map[string]interface{}, start, end sqltypes.Value) *sqlparser.Where {
	var startClause *sqlparser.ComparisonExpr
	var endClause *sqlparser.ComparisonExpr
	var clauses sqlparser.BoolExpr
	// No upper or lower bound, just return the where clause of original query
	if start.IsNull() && end.IsNull() {
		return whereClause
	}
	pk := &sqlparser.ColName{
		Name: sqlparser.SQLName(qs.splitColumn),
	}
	if !start.IsNull() {
		startClause = &sqlparser.ComparisonExpr{
			Operator: sqlparser.GreaterEqualStr,
			Left:     pk,
			Right:    sqlparser.ValArg([]byte(":" + startBindVarName)),
		}
		if start.IsNumeric() {
			v, _ := start.ParseInt64()
			bindVars[startBindVarName] = v
		} else if start.IsString() {
			bindVars[startBindVarName] = start.Raw()
		} else if start.IsFractional() {
			v, _ := start.ParseFloat64()
			bindVars[startBindVarName] = v
		}
	}
	// splitColumn < end
	if !end.IsNull() {
		endClause = &sqlparser.ComparisonExpr{
			Operator: sqlparser.LessThanStr,
			Left:     pk,
			Right:    sqlparser.ValArg([]byte(":" + endBindVarName)),
		}
		if end.IsNumeric() {
			v, _ := end.ParseInt64()
			bindVars[endBindVarName] = v
		} else if end.IsString() {
			bindVars[endBindVarName] = end.Raw()
		} else if end.IsFractional() {
			v, _ := end.ParseFloat64()
			bindVars[endBindVarName] = v
		}
	}
	if startClause == nil {
		clauses = endClause
	} else {
		if endClause == nil {
			clauses = startClause
		} else {
			// splitColumn >= start AND splitColumn < end
			clauses = &sqlparser.AndExpr{
				Left:  startClause,
				Right: endClause,
			}
		}
	}
	if whereClause != nil {
		clauses = &sqlparser.AndExpr{
			Left:  &sqlparser.ParenBoolExpr{Expr: whereClause.Expr},
			Right: &sqlparser.ParenBoolExpr{Expr: clauses},
		}
	}
	return &sqlparser.Where{
		Type: sqlparser.WhereStr,
		Expr: clauses,
	}
}