forked from sheetjs/docs.sheetjs.com
		
	
		
			
	
	
		
			89 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
		
		
			
		
	
	
			89 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
|  | const Knex = require('knex'); | ||
|  | const XLSX = require("xlsx"); | ||
|  | 
 | ||
|  | /* read file and get first worksheet */ | ||
|  | const oldwb = XLSX.readFile("pres.numbers"); | ||
|  | const oldws = oldwb.Sheets[oldwb.SheetNames[0]]; | ||
|  | 
 | ||
|  | /* create table and load data given an array of objects and a Knex connection */ | ||
|  | async function aoo_to_knex_table(knex, aoo, table_name) { | ||
|  |   /* define types that can be converted (e.g. boolean can be stored in float) */ | ||
|  |   const T_FLOAT = ["float", "boolean"]; | ||
|  |   const T_BOOL = ["boolean"]; | ||
|  | 
 | ||
|  |   /* types is a map from column headers to Knex schema column type */ | ||
|  |   const types = {}; | ||
|  | 
 | ||
|  |   /* names is an ordered list of the column header names */ | ||
|  |   const names = []; | ||
|  | 
 | ||
|  |   /* loop across each row object */ | ||
|  |   aoo.forEach(row => | ||
|  |     /* Object.entries returns a row of [key, value] pairs */ | ||
|  |     Object.entries(row).forEach(([k,v]) => { | ||
|  | 
 | ||
|  |       /* If this is first occurrence, mark unknown and append header to names */ | ||
|  |       if(!types[k]) { types[k] = ""; names.push(k); } | ||
|  | 
 | ||
|  |       /* skip null and undefined values */ | ||
|  |       if(v == null) return; | ||
|  | 
 | ||
|  |       /* check and resolve type */ | ||
|  |       switch(typeof v) { | ||
|  |         /* change type if it is empty or can be stored in a float */ | ||
|  |         case "number": if(!types[k] || T_FLOAT.includes(types[k])) types[k] = "float"; break; | ||
|  |         /* change type if it is empty or can be stored in a boolean */ | ||
|  |         case "boolean": if(!types[k] || T_BOOL.includes(types[k])) types[k] = "boolean"; break; | ||
|  |         /* no other type can hold strings */ | ||
|  |         case "string": types[k] = "text"; break; | ||
|  |         default: types[k] = "text"; break; | ||
|  |       } | ||
|  |     }) | ||
|  |   ); | ||
|  | 
 | ||
|  |   /* Delete table if it exists in the DB */ | ||
|  |   await knex.schema.dropTableIfExists(table_name); | ||
|  | 
 | ||
|  |   /* use column type info to create table */ | ||
|  |   await knex.schema.createTable(table_name, (table) => { | ||
|  |     names.forEach(h => { | ||
|  |       /* call schema function e.g. table.text("Name"); table.float("Index"); */ | ||
|  |       table[types[h] || "text"](h); | ||
|  |     }); | ||
|  |   }); | ||
|  | 
 | ||
|  |   /* insert each row */ | ||
|  |   await knex.insert(aoo).into(table_name); | ||
|  |   return knex; | ||
|  | } | ||
|  | 
 | ||
|  | (async() => { | ||
|  |   /* open connection to SheetJSKnex.db */ | ||
|  |   let knex = Knex({ client: 'better-sqlite3', connection: { filename: "SheetJSKnex.db" }, useNullAsDefault: true }); | ||
|  | 
 | ||
|  |   try { | ||
|  |     /* generate array of objects from worksheet */ | ||
|  |     const aoo = XLSX.utils.sheet_to_json(oldws); | ||
|  | 
 | ||
|  |     /* create table and load data */ | ||
|  |     await aoo_to_knex_table(knex, aoo, "Test_Table"); | ||
|  |   } finally { | ||
|  |     /* disconnect */ | ||
|  |     knex.destroy(); | ||
|  |   } | ||
|  | 
 | ||
|  |   /* reconnect to SheetJSKnex.db */ | ||
|  |   knex = Knex({ client: 'better-sqlite3', connection: { filename: "SheetJSKnex.db" }, useNullAsDefault: true }); | ||
|  | 
 | ||
|  |   try { | ||
|  |     /* get data from db */ | ||
|  |     const aoo = await knex.select("*").from("Test_Table"); | ||
|  | 
 | ||
|  |     /* export to file */ | ||
|  |     const newws = XLSX.utils.json_to_sheet(aoo); | ||
|  |     const newwb = XLSX.utils.book_new(); | ||
|  |     XLSX.utils.book_append_sheet(newwb, newws, "Export"); | ||
|  |     XLSX.writeFile(newwb, "SheetJSKnex.xlsx"); | ||
|  |   } finally { knex.destroy(); } | ||
|  | })(); |