SQL to Go struct

README.md

SQL to Go struct

Simple program to transform SQL queries to go structs.

The fields need to have a as clause for now.

Example

SELECT inbounds.count as inbounds_count,
    inbounds.last_week as inbounds_last_week,
    inbounds.most_active_user as inbounds_most_active_user,
    outbounds.count as outbounds_count,
    outbounds.last_week as outbounds_last_week,
    outbounds.most_active_user as outbounds_most_active_user,
    locations.count as locations_count,
    users.count as user_count,
    items.count as items_count,
    items.avg_price as items_avg_price,
    items.total_price as items_total_price
FROM .....

Outputs

type AutoGenerated struct {
	InboundsCount string `json:"inbounds_count"`
	InboundsLastWeek string `json:"inbounds_last_week"`
	InboundsMostActiveUser string `json:"inbounds_most_active_user"`
	OutboundsCount string `json:"outbounds_count"`
	OutboundsLastWeek string `json:"outbounds_last_week"`
	OutboundsMostActiveUser string `json:"outbounds_most_active_user"`
	LocationsCount string `json:"locations_count"`
	UserCount string `json:"user_count"`
	ItemsCount string `json:"items_count"`
	ItemsAvgPrice string `json:"items_avg_price"`
	ItemsTotalPrice string `json:"items_total_price"`
}

queryToStruct.go

package main

import (
	"bufio"
	"bytes"
	"os"
	"regexp"
	"strings"
)

var FieldRegex = regexp.MustCompile(`[SELECTselect\s]*\w+\.\w+\s*as\s*(\w+)[,\s]*`)

func main() {
	r := bufio.NewReader(os.Stdin)
	buf := &bytes.Buffer{}
	for {
		s, err := r.ReadString('\n')
		buf.WriteString(s)
		if err != nil {
			break
		}
	}

	fields := FieldRegex.FindAllStringSubmatch(buf.String(), -1)
	finalFields := make([]string, 0)
	for _, f := range fields {
		finalFields = append(finalFields, f[1])
	}

	strc := BuildStructFromFields(finalFields)

	os.Stdout.WriteString(strc)
}

// BuildStructFromFields builds a go struct from a slice of fields
func BuildStructFromFields(fields []string) string {
	var buf bytes.Buffer
	buf.WriteString("type ")
	buf.WriteString("AutoGenerated")
	buf.WriteString(" struct {\n")
	for _, f := range fields {
		f = strings.Trim(f, "\n")
		buf.WriteString("\t" + ToPascal(f) + " ")
		buf.WriteString("string")
		// add struct tags
		buf.WriteString(" `json:\"" + f + "\"`\n")
	}
	buf.WriteString("}\n")
	return buf.String()
}

// ToPascal takes in a string in snake case and returns the PascalCase version
func ToPascal(s string) string {
	// Split the string on underscores
	parts := strings.Split(s, "_")
	for i, p := range parts {
		// Capitalize the string
		parts[i] = strings.Title(p)
	}
	return strings.Join(parts, "")
}