Create knex.js migration for existing database. Input Database structure in the form of create table SQL statements, and this ejs template can create Knex.js migration

gen-knex-migration.ejs

<%
const Parser = require('sql-ddl-to-json-schema');
const fs = require('fs');

const [ sqlFileName ] = argv;
if( !sqlFileName ) throw new Error('SQL file not specified');
const parser = new Parser('mysql');
parser.feed( fs.readFileSync( sqlFileName, 'utf-8'));

const data = parser.toCompactJson();

// const data = parser.toJsonSchemaArray();
// const util = require('util');
// console.log( util.inspect( data, { depth: null }));
// process.exit();
// console.log( JSON.stringify( data ));

// data = JSON.parse( dataStr );
var typemap = {
  int: 'integer',
  text: 'text',
  varchar: 'string',
  timestamp: 'timestamp',
  datetime: 'datetime',
  enum: 'enum'

};

function getType( col ){
  if( col.options.autoincrement ){
    return 'increments';
  }
  const out = typemap[col.type.datatype];
  if( out === undefined ){ throw 'Unknown column: ' + col.type.datatype }
  return out;
}

function getLen( col ){
    var out;
    var t = col.type;
    switch( t.datatype ){
        case 'int':
            out = t.width;
            break;
        case 'varchar':
            out = t.length;
            break;
        case 'enum':
            out = "['" + t.values.join("','") + "']";
            break;
    }
    if( out !== undefined ){
        return ', ' + out;
    }
    return ''
}
var timestampCols = ['timestamp', 'datetime'];

function getDefVal(col){
    if( ( timestampCols.indexOf(col.type.datatype) !== -1)  && col.options.default === 'current_timestamp()'){
        return 'knex.fn.now()';
    }
    return `'${col.options.default}'`;
}
function getFkCols( cols ){
    return cols.map( v => v.column ).toString();
}
function capitalize( str ){
    return str.charAt(0).toUpperCase() + str.slice(1);
}
%>

exports.up = async function(knex) {
<% data.forEach( function( tbl ){ %>
await knex.schema.createTable('<%-tbl.name -%>', function(table) {

    /* Column defnitions */
<% tbl.columns.forEach( function( col ){ -%>
	table.<%-getType( col )-%>('<%- col.name -%>'<%- getLen(col); _%>)
		<%_ if(col.options.autoincrement){ _%>
		.primary()
		<%_}_%>
		<%_ if(col.options.unsigned){ _%>
		.unsigned()
		<%_}_%>
		<%_ if(col.options.nullable === false ){ _%>
		.notNullable()
		<%_}_%>
		<%_ if( [undefined,null].indexOf(col.options.default) === -1 ){ _%>
		.defaultTo(<%- getDefVal( col )  -%>)
		<%_}_%>

<% }) %>
    /* Column defnitions */
<% if(tbl.foreignKeys) {%>
    /* Foreign key defnitions */
<% tbl.foreignKeys.forEach( function( fk ){ -%>
    table.foreign('<%- getFkCols(fk.columns) -%>')
        .references('<%- getFkCols(fk.reference.columns ) -%>')
<% fk.reference.on && fk.reference.on.forEach( function( on ){ -%>
        .on<%- capitalize(on.trigger) -%>('<%- on.action -%>')
<% }) -%>
        .inTable('<%-fk.reference.table-%>');

<% }) %>
    /* Foreign key defnitions */
<%}%>
<% if(tbl.uniqueKeys) {%>
    /* Unique key indexes */
<% tbl.uniqueKeys.forEach( function( uk ){ -%>
    table.unique('<%- getFkCols(uk.columns) -%>');
<% }) %>
    /* Unique key indexes */
<%}%>
});

<% })%>
}; 

exports.down = async function(knex) {

	await knex.schema
<% data.reverse().forEach( function( tbl ){ _%>
		.dropTable('<%- tbl.name -%>')
<% }) _%>

};