--- title: AlaSQL pagination_prev: demos/desktop/index pagination_next: demos/local/index sidebar_custom_props: sql: true --- import current from '/version.js'; AlaSQL is a pure JavaScript in-memory SQL database. It has built-in support for SheetJS through the `XLSX` target operator. This demo covers basic concepts pertaining to data import and export. The official documentation includes advanced examples and deployment tips as well as strategies for general data processing in AlaSQL expressions. :::note This demo was tested in the following environments: | Environment | AlaSQL | Date | |:--------------------|:-------|:----------:| | NodeJS | 3.1.0 | 2023-02-23 | | Standalone (Chrome) | 3.0.0 | 2023-04-09 | ::: ## Live Demo This demo fetches , performs a `SELECT` query using the built-in AlaSQL + SheetJS integration, then displays the result. Using the result as a data source, the demo will write to a new spreadsheet.
Demo AlaSQL Queries (click to show) ```sql title="AlaSQL Query for reading data from a workbook" SELECT `Index`, -- "Index" field is the "Index" column of the sheet UPPER(`Name`) AS `Nom` -- "Nom" field will be uppercase of "Name" column FROM XLSX(?, { -- Parse the workbook bytes passed to alasql.promise autoExt: false -- This option is required in the browser }) ``` ```sql title="AlaSQL Query for writing data to a workbook" SELECT * -- use every field from every row in dataset INTO XLSX( -- export data to file "SheetJSAlaSQL.xlsx" -- filename for export ) FROM ? ```
:::caution If the live demo shows a message ``` alasql undefined ``` please refresh the page. This is a known bug in the documentation generator. ::: ```jsx live function SheetJSAlaSQL() { const q1 = "SELECT `Index`, UPPER(`Name`) AS `Nom` FROM XLSX(?,{autoExt:false})"; const q2 = `SELECT * INTO XLSX("SheetJSAlaSQL.xlsx") FROM ?`; const url = "https://sheetjs.com/pres.numbers"; const [rows, setRows] = React.useState([]); const loadURL = React.useCallback(async() => { if(typeof alasql=="undefined") return setRows([{Nom:"alasql undefined"}]); const blob = await (await fetch(url)).blob(); const data = URL.createObjectURL(blob); const res = await alasql.promise(q1,[data]); setRows(res); await alasql.promise(q2, [res]); }, []); return ( <>
URL: {url}
Import: {q1}
Export: {q2}
{rows.map(({Nom, Index}) => )}
IndexNom
{Index}{Nom}
); } ``` ## Browser #### Standalone Scripts The [Standalone scripts](/docs/getting-started/installation/standalone) should be loaded before the `alasql` script: ```html ``` #### Frameworks and Bundlers `alasql` uses an older version of the library. It can be overridden through a `package.json` override. The lines should be added *before* installing `alasql`:
{`\
{
  /* add this part before "name" */
  /* highlight-start */
  "overrides": {
    "xlsx": "https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz"
  },
  /* highlight-end */
  "name": "my-project",
  /* ... more fields ... */
`}
After adding the override, AlaSQL can be installed through `npm`: ```bash npm install --save alasql ``` In imports, the SheetJS library must be passed to AlaSQL as shown below: ```js import * as alasql from 'alasql'; import * as XLSX from 'xlsx'; alasql.utils.isBrowserify = false; alasql.utils.global.XLSX = XLSX; ``` ### Reading Files The `XLSX` "from" target expects a filename. In the browser, AlaSQL uses object URLs which can be created from `Blob` or `File` objects. The following snippet fetches data and passes to AlaSQL: ```js const blob = await (await fetch("https://sheetjs.com/pres.numbers")).blob(); const data = URL.createObjectURL(blob); const res = await alasql.promise("SELECT * FROM XLSX(?, {autoExt: false}", [data]); ``` By default, the `XLSX` "from" target automatically adds a `.xlsx` extension. To read URLs, the `autoExt: false` option should be passed as the second argument: ```sql SELECT `Name`, `Index` FROM XLSX( ? --<< this will be the URL passed into `alasql.promise` // highlight-start , { --<< options are supplied as the second argument to XLSX operator autoExt: false --<< do not automatically add ".xlsx" extension! } // highlight-end ) WHERE `Index` < 45 ``` By default the workbook is parsed and `sheet_to_json` is used to pull data: ```js (async() => { const blob = await (await fetch("https://sheetjs.com/pres.numbers")).blob(); const data = URL.createObjectURL(blob); const aoo = await alasql.promise("SELECT * FROM XLSX(?, {autoExt: false}", [data]); console.log(aoo); // [ { Name: "Bill Clinton", Index: 42 }, ...] })(); ``` ### Writing Files The `XLSX` "into" target calls `XLSX.writeFile` under the hood: ```js const { promise: alasql } = require("alasql"); (async() => { const data = [ { Name: "Bill Clinton", Index: 42 }, { Name: "Someone Else", Index: 47 } ]; await alasql(`SELECT * INTO XLSX("PresMod5.xlsx") FROM ?`, [data]); /* PresMod5.xlsx will be created */ })(); ``` ## NodeJS :::caution `alasql` uses an older version of the library. It can be overridden through a `package.json` override in the latest versions of NodeJS:
{`\
{
  "overrides": {
    "xlsx": "https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz"
  }
}`}
::: ### Reading Files By default, the `XLSX` "from" target automatically adds a `.xlsx` extension. To read files with an arbitrary filename, the `autoExt: false` option should be passed as the second argument: ```sql SELECT `Name`, `Index` FROM XLSX( "pres.numbers" --<< filename is "pres.numbers" // highlight-start , { --<< options are supplied as the second argument to XLSX operator autoExt: false --<< do not automatically add ".xlsx" extension! } // highlight-end ) WHERE `Index` < 45 ``` By default the workbook is parsed and `sheet_to_json` is used to pull data: ```js const { promise: alasql } = require("alasql"); (async() => { const aoo = await alasql(`SELECT * from XLSX("pres.xlsx", {autoExt: false})`); console.log(aoo); // [ { Name: "Bill Clinton", Index: 42 }, ...] })(); ``` ### Writing Files The `XLSX` "into" target calls `XLSX.writeFile` under the hood: ```js const { promise: alasql } = require("alasql"); (async() => { const data = [ { Name: "Bill Clinton", Index: 42 }, { Name: "Someone Else", Index: 47 } ]; await alasql(`SELECT * INTO XLSX("PresMod5.xlsx") FROM ?`, [data]); /* PresMod5.xlsx will be created */ })(); ``` ### NodeJS Example 1) Create an empty folder for the project: ```bash mkdir alasql cd alasql ``` 2) In the folder, create a stub `package.json` with the `xlsx` override: ```json title="package.json" { "overrides": { "xlsx": "https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz" } } ``` 3) Install SheetJS and AlaSQL: ```bash npm i --save alasql@3.1.0 https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz ``` 4) Download the test file : ```bash curl -LO https://sheetjs.com/pres.numbers ``` 5) Save the following test script to `SheetJSAlaSQL.js`: ```js title="SheetJSAlaSQL.js" const { promise: alasql } = require("alasql"); (async() => { /* read data from spreadsheet to JS */ const data = await alasql(` SELECT \`Name\`, \`Index\` FROM XLSX("pres.numbers", {autoExt:false}) WHERE \`Index\` < 45 `); console.log(data); /* write data from JS to spreadsheet */ data.push({Name: "Someone Else", Index: 47}); await alasql(`SELECT * INTO XLSX("SheetJSAlaSQL1.xlsx") FROM ?`, [data]); })(); ``` 6) Run the test script ```bash node SheetJSAlaSQL.js ``` The output should display: ``` [ { Name: 'Bill Clinton', Index: 42 }, { Name: 'GeorgeW Bush', Index: 43 }, { Name: 'Barack Obama', Index: 44 } ] ``` The script should generate `SheetJSAlaSQL1.xlsx` with the additional row: ```csv Name,Index Bill Clinton,42 GeorgeW Bush,43 Barack Obama,44 Someone Else,47 ```