query-interpreter/q/dto.go

package q

import (
	"encoding/json"
	"strings"
)

const NONE = 0

type QueryType int

const (
	SELECT QueryType = iota + 1
	UPDATE
	INSERT
	DELETE
)

// QueryTypeString converts a QueryType integer to its string representation.
func QueryTypeString(t QueryType) string {
	switch t {
	case SELECT:
		return "SELECT"
	case UPDATE:
		return "UPDATE"
	case INSERT:
		return "INSERT"
	case DELETE:
		return "DELETE"
	default:
		return "UNKNOWN"
	}
}

type Table struct {
	Name  string `json:"name"`
	Alias string `json:"alias"`
}

type Conditional struct {
	Key       string `json:"key"`
	Operator  string `json:"operator"`
	Value     string `json:"value"`
	Extension string `json:"extension"`
}

type AggregateFunctionType int

const (
	MIN AggregateFunctionType = iota + 1
	MAX
	COUNT
	SUM
	AVG
)

// AggregateFunctionTypeString converts an AggregateFunctionType integer to its string representation.
func AggregateFunctionTypeString(t AggregateFunctionType) string {
	switch t {
	case MIN:
		return "MIN"
	case MAX:
		return "MAX"
	case COUNT:
		return "COUNT"
	case SUM:
		return "SUM"
	case AVG:
		return "AVG"
	default:
		return "UNKNOWN"
	}
}

// Converts the string name of AggregateFunctionType into it original int
func AggregateFunctionTypeByName(name string) AggregateFunctionType {
	var functionType AggregateFunctionType
	switch strings.ToUpper(name) {
	case "MIN":
		functionType = MIN
	case "MAX":
		functionType = MAX
	case "COUNT":
		functionType = COUNT
	case "SUM":
		functionType = SUM
	case "AVG":
		functionType = AVG
	default:
		functionType = 0
	}

	return functionType
}

type JoinType int

const (
	INNER JoinType = iota
	LEFT
	RIGHT
	FULL
	SELF
)

// JoinTypeString converts a JoinType integer to its string representation.
func JoinTypeString(t JoinType) string {
	switch t {
	case INNER:
		return "INNER"
	case LEFT:
		return "LEFT"
	case RIGHT:
		return "RIGHT"
	case FULL:
		return "FULL"
	case SELF:
		return "SELF"
	default:
		return "UNKNOWN"
	}
}

type Column struct {
	Name              string                `json:"name"`
	Alias             string                `json:"alias"`
	AggregateFunction AggregateFunctionType `json:"aggregateFunction"`
}

type Join struct {
	Type         JoinType      `json:"type"`
	MainTable    Table         `json:"mainTable"`
	JoiningTable Table         `json:"joiningTable"`
	Ons          []Conditional `json:"ons"`
}

type OrderBy struct {
	Key       string `json:"key"`
	IsDescend bool   `json:"isDescend"`
}

type Select struct {
	Type         QueryType     `json:"type"`
	Table        Table         `json:"table"`
	Columns      []Column      `json:"columns"`
	Conditionals []Conditional `json:"conditionals"`
	OrderBys     []OrderBy     `json:"orderBys"`
	Joins        []Join        `json:"joins"`
	IsWildcard   bool          `json:"isWildcard"`
	IsDistinct   bool          `json:"is_distinct"`
}

func MarshalSelect(selectStatement Select) ([]byte, error) {
	jsonData, err := json.MarshalIndent(selectStatement, "", "  ")
	return jsonData, err
}

//func test() {
//selectStatement := Select{
//	Table: "users",
//	Columns: []Column{
//		{Name: "id", Alias: "user_id", AggregateFunction: COUNT},
//	},
//	Conditionals: []Conditional{
//		{Key: "age", Operator: ">", Value: "18"},
//	},
//	OrderBys: []OrderBy{
//		{Key: "name", IsDescend: false},
//	},
//	Joins: []Join{
//		{
//			Type:  LEFT,
//			Table: Table{Name: "orders"},
//			Ons:   []Conditional{{Key: "user_id", Operator: "=", Value: "users.id"}},
//		}},
//}
//
//jsonData, err := json.MarshalIndent(selectStatement, "", "  ")
//if err != nil {
//	fmt.Println("Error marshaling JSON:", err)
//	return
//}
//
//fmt.Println(string(jsonData))
//
//fmt.Println(QueryTypeString(SELECT))
//fmt.Println(AggregateFunctionTypeString(MAX))
//fmt.Println(JoinTypeString(INNER))
//}