ar.go

package main

import (
	"bytes"
	"strconv"
)

////
// Query Builder
//
type Query struct {
	Clauses []string
	Table   string
}

func (q *Query) Find(id int64) *Query {
	idAsString := strconv.Itoa(int(id))
	q.Clauses = append(q.Clauses, "WHERE 'id' = "+idAsString+"")
	return q
}

func (q *Query) Limit(n int) *Query {
	cardinalityAsString := strconv.Itoa(int(n))
	q.Clauses = append(q.Clauses, "LIMIT "+cardinalityAsString)
	return q
}

func (q *Query) Where(column string, value string) *Query {
	q.Clauses = append(q.Clauses, "WHERE '"+column+"' = '"+value+"'")
	return q
}

func (q *Query) ToSql() string {
	var sqlBuffer bytes.Buffer
	sqlBuffer.WriteString("SELECT * FROM '" + q.Table + "'")

	for index, clause := range q.Clauses {
		// Check if it's an AND clause
		if index > 0 {
			sqlBuffer.WriteString(" AND")
		}

		sqlBuffer.WriteString(" " + clause)
	}

	return sqlBuffer.String()
}

////
// Constructors
//
func Table(name string) *Query {
	query := NewQuery()
	query.Table = name
	return query
}

func NewQuery() *Query {
	return &Query{}
}

ar_test.go

package main

import (
	"testing"
)

func TestLimitFunction(t *testing.T) {
	sql := Table("products").Limit(44).ToSql()
	if sql != "SELECT * FROM 'products' LIMIT 44" {
		t.Error("Bad sql generated")
	}
}

func TestFindFunction(t *testing.T) {
	sql := Table("products").Find(123).ToSql()
	if sql != "SELECT * FROM 'products' WHERE 'id' = 123" {
		t.Error("Bad sql generated")
	}
}

func TestTableFunction(t *testing.T) {
	sql := Table("products").ToSql()
	if sql != "SELECT * FROM 'products'" {
		t.Error("Bad sql generated")
	}
}

func TestWhereFunction(t *testing.T) {
	sql := Table("products").Where("name", "T-shirt").ToSql()
	if sql != "SELECT * FROM 'products' WHERE 'name' = 'T-shirt'" {
		t.Error("Bad sql generated")
	}

	sql = Table("products").Where("name", "T-shirt").Where("me", "you").ToSql()
	if sql != "SELECT * FROM 'products' WHERE 'name' = 'T-shirt' AND WHERE 'me' = 'you'" {
		t.Error("Bad sql generated")
	}
}