tdconv

A golang package and tool for converting table definitions to SQL and Go struct etc.

• Description
  • Package tdconv
  • Tool tdconverter
• Install
• Requirements
• Usage

Description

Package tdconv

This package converts table definitions to SQL and Go struct etc. Currently this package supports SQL and Go format.

For example, if the table definition is like...

SQL is output as follows.

# This file generated by tdconv. DO NOT EDIT.
# See more details at https://github.com/takuoki/tdconv.
DROP TABLE IF EXISTS sample_table;
CREATE TABLE `sample_table` (
    `id` INT UNSIGNED NOT NULL AUTO_INCREMENT COMMENT 'this is id!',
    `foo` VARCHAR(32) NOT NULL UNIQUE,
    `bar` VARCHAR(32),
    PRIMARY KEY (id),
    INDEX `bar_key` (bar)
);

Go struct is output as follows.

// This file generated by tdconv. DO NOT EDIT.
// See more details at https://github.com/takuoki/tdconv.
package main

import(
  "time"
)

type sampleTable struct {
  ID *int
  Foo *string
  Bar *string
}

You can change the header and footer text as you want. If you want to output with new format, you can do it with creating a new Formatter. And more, if the parsed Table data are not enough for you, you can modify them as you want. For usage of this package, see the standard tool which uses this package.

Tool tdconverter

This is a standard tool uses the package tdconv. For more details, see README.md.

Install

You can install this tool using go get. Before installing, enable the Go module feature.

go get github.com/takuoki/tdconv

Requirements

On parsing, this package uses Sheet objects in github.com/takuoki/gsheets package. For more details, see README.md in this package.

Usage

First, create a new Parser. If your sheet is different from the default sheet format, set ParseOption to match your sheet. And if you need some common columns to all tables, set them with SetCommonColumns method.

p, err := tdconv.NewParser()
if err != nil {
  return nil, fmt.Errorf("Unable to create new parser: %v", err)
}

err = p.SetCommonColumns(commonSheet)
if err != nil {
  return nil, fmt.Errorf("Unable to parse common sheet information: %v", err)
}

Then, parse your sheet with Parse method. Basically, just specify the sheet value returns by GetSheet method of the gsheets package. In case of parsing multiple sheets, loop it in your application.

var tables []*tdconv.Table
for _, sheetname := range sheets {
  sheet, err := gclient.GetSheet(ctx, id, sheetname)
  if err != nil {
    return nil, fmt.Errorf("Unable to get sheet values (sheetname=%s): %v", sheetname, err)
  }
  table, err := p.Parse(sheet)
  if err != nil {
    return nil, fmt.Errorf("Unable to parse sheet information (sheetname=%s): %v", sheetname, err)
  }
  tables = append(tables, table)
}

Finally, create TableSet based on some Tables you get above step, and output file(s) with formatter you need. For SQLFormatter or GoFormatter, you can change the header and footer text with SQLFormatOption or GoFormatOption. If the parsed Table data are not enough for you, you can modify them as you want before calling the Output function. If the multi flag, which is one of the arguments of the Output function, is true, one file is output for each Table. If false, one file is output for each TableSet.

tableSet := &tdconv.TableSet{
  Name:   title,
  Tables: tables,
}

f, err := tdconv.NewSQLFormatter()
if err != nil {
  return fmt.Errorf("Fail to create SQL formatter: %v", err)
}

if err := tdconv.Output(f, tableSet, multi, outdir); err != nil {
  return fmt.Errorf("Fail to output table definitions: %v", err)
}

If you create a new formatter, follow the Formatter interface below.

type Formatter interface {
  Fprint(w io.Writer, t *Table)
  Header(w io.Writer, ts *TableSet)
  TableHeader(w io.Writer, t *Table)
  TableFooter(w io.Writer, t *Table)
  Footer(w io.Writer, ts *TableSet)
  Extension() string
}

• Fprint: Output table contents. This is main method of this interface.
• Header: Output the header. This method is called only once for each file.
• TableHeader: Output the table headers. This method is called before calling Fprint method, and called multiple times if the multi flag is false.
• TableFooter: Output the table footers. This method is called after calling Fprint method, and called multiple times if the multi flag is false.
• Footer: Output the footer. This method is called only once for each file.
• Extension: Return file extension.