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import current from '/version.js'; import CodeBlock from '@theme/CodeBlock';
WebSQL is a popular SQL-based in-browser database available on Chrome. In practice, it is powered by SQLite, and most simple SQLite-compatible queries work as-is in WebSQL.
The public demo https://sheetjs.com/sql generates a database from workbook.
:::caution
WebSQL is only supported in Chromium-based browsers including Chrome.
Safari historically supported WebSQL but Safari 13 dropped support. Legacy browsers including Internet Explorer and Firefox never added support.
:::
WebSQL Details
Importing data from spreadsheets is straightforward using the generate_sql
helper function from "Generating Tables".
The Web SQL Database API is callback-based. The following snippet wraps transactions in Promise objects:
const db = openDatabase('sheetql', '1.0', 'SheetJS WebSQL Test', 2097152);
const stmts = generate_sql(ws, wsname);
// NOTE: tx.executeSql and db.transaction use callbacks. This wraps in Promises
for(var stmt of stmts) await new Promise((res, rej) => {
db.transaction(tx =>
tx.executeSql(stmt, [],
(tx, data) => res(data), // if the query is successful, return the data
(tx, err) => rej(err) // if the query fails, reject with the error
));
});
The result of a SQL SELECT statement is a SQLResultSet
. The rows
property
is a SQLResultSetRowList
. It is an "array-like" structure that has length
and properties like 0
, 1
, etc. However, this is not a real Array object!
A real Array can be created using Array.from
:
db.readTransaction(tx =>
tx.executeSQL("SELECT * FROM DatabaseTable", [], (tx, data) => {
// data.rows is "array-like", so `Array.from` can make it a real array
const aoo = Array.from(data.rows);
const ws = XLSX.utils.json_to_sheet(aoo);
// ... perform an export here OR wrap in a Promise
})
);
Live Demo
:::note
This demo was last tested on 2023 May 28 in Chromium 113
:::
The following demo generates a database with 5 fixed SQL statements. Queries can be changed in the Live Editor. The WebSQL database can be inspected in the "WebSQL" section of the "Application" Tab of Developer Tools:
function SheetQL() {
const [out, setOut] = React.useState("");
const queries = [
'DROP TABLE IF EXISTS Presidents',
'CREATE TABLE Presidents (Name TEXT, Idx REAL)',
'INSERT INTO Presidents (Name, Idx) VALUES ("Barack Obama", 44)',
'INSERT INTO Presidents (Name, Idx) VALUES ("Donald Trump", 45)',
'INSERT INTO Presidents (Name, Idx) VALUES ("Joseph Biden", 46)'
];
const xport = React.useCallback(async() => {
/* prep database */
const db = openDatabase('sheetql', '1.0', 'SheetJS WebSQL Test', 2097152);
for(var q of queries) await new Promise((res, rej) => {
db.transaction((tx) => {
tx.executeSql(q, [], (tx, data) => res(data), (tx, err) => rej(err));
});
});
/* pull data and generate rows */
db.readTransaction(tx => {
tx.executeSql("SELECT * FROM Presidents", [], (tx, data) => {
const aoo = Array.from(data.rows);
setOut("QUERY RESULT:\n" + aoo.map(r => JSON.stringify(r)).join("\n") + "\n")
const ws = XLSX.utils.json_to_sheet(aoo);
const wb = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, ws, "Presidents");
XLSX.writeFile(wb, "SheetQL.xlsx");
});
});
});
return ( <pre>{out}<button onClick={xport}><b>Fetch!</b></button></pre> );
}
Server-Side SQLite
Most platforms offer a simple way to query SQLite database files.
The following example shows how to query for each table in an SQLite database, query for the data for each table, add each non-empty table to a workbook, and export as XLSX.
The Chinook database is a MIT-licensed sample database. The original source code
repository http://chinookdatabase.codeplex.com
is no longer available, so the
raw SQL queries are mirrored here.
:::note
This demo was last tested on 2023 May 28
:::
NodeJS
The better-sqlite3
module provides an API for working with SQLite databases.
Statement#all
runs a prepared statement and returns an array of objects:
import Database from "better-sqlite3";
import * as XLSX from "xlsx";
/* open database */
var db = Database("chinook.db");
/* get data from the `Invoice` table */
var aoo = db.prepare("SELECT * FROM 'Invoice' LIMIT 100000").all();
/* create worksheet from the row objects */
var ws = XLSX.utils.json_to_sheet(aoo, {dense: true});
- Build
chinook.db
from the SQL statements:
curl -LO https://docs.sheetjs.com/sqlite/chinook.sql
sqlite3 chinook.db ".read chinook.sql"
- Install the dependencies:
{\ npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz better-sqlite3@8.1.0
}
- Download
SheetJSQLiteNode.mjs
:
curl -LO https://docs.sheetjs.com/sqlite/SheetJSQLiteNode.mjs
- Run
node SheetJSQLiteNode.mjs
and openSheetJSQLiteNode.xlsx
Bun
Bun ships with a built-in high-performance module bun:sqlite
:
import { Database } from "bun:sqlite";
import * as XLSX from "xlsx";
/* open database */
var db = Database.open("chinook.db");
/* get data from the `Invoice` table */
var aoo = db.prepare("SELECT * FROM 'Invoice' LIMIT 100000").all();
/* create worksheet from the row objects */
var ws = XLSX.utils.json_to_sheet(aoo, {dense: true});
- Build
chinook.db
from the SQL statements:
curl -LO https://docs.sheetjs.com/sqlite/chinook.sql
sqlite3 chinook.db ".read chinook.sql"
- Install the dependencies:
{\ npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz
}
- Download
SheetJSQLiteBun.mjs
:
curl -LO https://docs.sheetjs.com/sqlite/SheetJSQLiteBun.mjs
- Run
bun run SheetJSQLiteBun.mjs
and openSheetJSQLiteBun.xlsx
Deno
Deno sqlite
library returns raw arrays of arrays:
{\ import { DB } from "https://deno.land/x/sqlite/mod.ts"; // @deno-types="https://cdn.sheetjs.com/xlsx-${current}/package/types/index.d.ts" import * as XLSX from "https://cdn.sheetjs.com/xlsx-${current}/package/xlsx.mjs"; \n\ /* open database */ var db = new DB("chinook.db"); \n\ /* get data from the \
Invoice` table /
var aoa = db.prepareQuery("SELECT * FROM 'Invoice' LIMIT 100000").all();
\n
/ create worksheet from the row objects */
var data = [query.columns().map(x => x.name)].concat(aoa);
var ws = XLSX.utils.aoa_to_sheet(data, {dense: true});`}
- Build
chinook.db
from the SQL statements:
curl -LO https://docs.sheetjs.com/sqlite/chinook.sql
sqlite3 chinook.db ".read chinook.sql"
- Download
SheetJSQLiteDeno.ts
:
curl -LO https://docs.sheetjs.com/sqlite/SheetJSQLiteDeno.ts
- Run
deno run --allow-read --allow-write SheetJSQLiteDeno.ts
and openSheetJSQLiteDeno.xlsx