Crafting Table

A function creation tool for querying to database from golang struct. It uses sqlx package to connect to database.

How to use Crafting Table?

The Command for creating functions is as below.

crafting-table generate \
      -s ./SOURCE/PATH/STRUCTFILE.go \
      -d ./DESTINATIOIN/PATH/REPOSITORY.go \
      --get "[ GetByVar1, (GetByVar1, GetByVar3) ]" \
      --update "[[(UpdateByVar3),(UpdateVar2, UpdateVar1)], [(UpdateByVar2, UpdateByVar3), (UpdateVar1)]]" \
      --create true

Flags

Flag	Description
-s	Source file path.
-d	Destination file path.
--get	Get function name and arguments. You can use multiple arguments separated with comma , to define multiple Get functions. Also, You can use parentheses to get records by more than one parameter. If you don't define this flag, Get function will not be created.
--update	Update function name and arguments. You can use multiple arguments separated with comma , and brackets [ ] to define multiple Update functions. You should define two pairs of parentheses in each bracket, the former for updating by parameters and the latter for updating fields parameters. If you don't define this flag, Update function will not be created.
--create	Create function name and arguments. If you don't define this flag, Create function will not be created.

Note

In each flag, you should use the database name as parameter.

Example

Suppose that the following struct is a table in the database.

package src

type Example struct {
	Var1 int    `db:"var1"`
	Var2 string `db:"var2"`
	Var3 bool   `db:"var3"`
}

You can create a functions to query to database using crafting-table as below.

Command:

crafting-table generate \
    -s ./example/src/example.go \
    -d ./example/dst/example.go \
    --get "[ var1, (var1, var3) ]" \
    --update "[[(var3), (var2, var1)], [(var2, var3), (var1)]]" \
    --create true

Result:

package repository

import (
	"context"
	"database/sql"
	"errors"
	"github.com/n25a/crafting-table/example/src"

	"github.com/jmoiron/sqlx"
)

type Example interface {
	Create(ctx context.Context, example *src.Example) error
	GetExamples(ctx context.Context) (*[]src.Example, error)
	GetByVar1(ctx context.Context, var1 int) (*src.Example, error)
	GetByVar1AndVar3(ctx context.Context, var1 int, var3 bool) (*src.Example, error)
	Update(ctx context.Context, var1 int, example src.Example) (int64, error)
	UpdateVar2AndVar1(ctx context.Context, var3 bool, var2 string, var1 int) (int64, error)
	UpdateVar1(ctx context.Context, var2 string, var3 bool, var1 int) (int64, error)
}

var ErrExampleNotFound = errors.New("example not found")

type mysqlExample struct {
	db *sqlx.DB
}

func NewMySQLExample(db *sqlx.DB) Example {
	return &mysqlExample{db: db}
}

func (r *mysqlExample) Create(ctx context.Context, example *src.Example) error {
	_, err := r.db.NamedExecContext(ctx, "INSERT INTO example ("+
		"var1, var2, var3"+
		") VALUES ("+
		":var1, :var2, :var3)",
		example)

	if err != nil {
		return err
	}

	return nil
}

func (r *mysqlExample) Update(ctx context.Context, var1 int, example src.Example) (int64, error) {
	example.Var1 = var1

	result, err := r.db.NamedExecContext(ctx, "UPDATE example "+
		"SET"+
		"var1 = :var1, var2 = :var2, var3 = :var3 "+
		"WHERE var1 = :var1",
		example,
	)

	if err != nil {
		return 0, err
	}

	return result.RowsAffected()
}

func (r *mysqlExample) UpdateVar2AndVar1(ctx context.Context, var3 bool, var2 string, var1 int) (int64, error) {
	query := "UPDATE example SET " +
		"var2 = ?, var1 = ? " +
		"WHERE var3 = ?;"

	result, err := r.db.ExecContext(ctx, query, var2, var1, var3)

	if err != nil {
		return 0, err
	}

	return result.RowsAffected()
}

func (r *mysqlExample) UpdateVar1(ctx context.Context, var2 string, var3 bool, var1 int) (int64, error) {
	query := "UPDATE example SET " +
		"var1 = ? " +
		"WHERE var2 = ? AND var3 = ?;"

	result, err := r.db.ExecContext(ctx, query, var1, var2, var3)

	if err != nil {
		return 0, err
	}

	return result.RowsAffected()
}

func (r *mysqlExample) GetExamples(ctx context.Context) (*[]src.Example, error) {
	var example []src.Example
	err := r.db.SelectContext(ctx, &example, "SELECT * from example")
	if err != nil {
		if err == sql.ErrNoRows {
			return nil, ErrExampleNotFound
		}

		return nil, err
	}

	return &example, nil
}

func (r *mysqlExample) GetByVar1(ctx context.Context, var1 int) (*src.Example, error) {
	var example src.Example

	err := r.db.GetContext(ctx, &example, "SELECT * FROM example "+
		"WHERE var1 = ?",
		var1,
	)

	if err != nil {
		if err == sql.ErrNoRows {
			return nil, ErrExampleNotFound
		}

		return nil, err
	}

	return &example, nil
}

func (r *mysqlExample) GetByVar1AndVar3(ctx context.Context, var1 int, var3 bool) (*src.Example, error) {
	var example src.Example

	err := r.db.GetContext(ctx, &example, "SELECT * FROM example "+
		"WHERE var1 = ? AND var3 = ?",
		var1, var3,
	)

	if err != nil {
		if err == sql.ErrNoRows {
			return nil, ErrExampleNotFound
		}

		return nil, err
	}

	return &example, nil
}

Help Us

You can contribute to improving this tool by sending pull requests or issues on GitHub. Please send us your feedback. Thanks!