A simple yet powerful module to allow you to use ES6 tagged template strings for prepared/escaped statements.
Works with mysql, mysql2, postgres and sequelize.
Example for escaping queries (callbacks omitted):
constSQL=require('sql-template-strings')constbook='harry potter'constauthor='J. K. Rowling'// mysql:mysql.query('SELECT author FROM books WHERE name = ? AND author = ?',[book,author])// is equivalent tomysql.query(SQL`SELECT author FROM books WHERE name = ${book} AND author = ${author}`)// postgres:pg.query('SELECT author FROM books WHERE name = $1 AND author = $2',[book,author])// is equivalent topg.query(SQL`SELECT author FROM books WHERE name = ${book} AND author = ${author}`)// sequelize:sequelize.query('SELECT author FROM books WHERE name = ? AND author = ?',{replacements: [book,author]})// is equivalent tosequelize.query(SQL`SELECT author FROM books WHERE name = ${book} AND author = ${author}`)This might not seem like a big deal, but when you do an INSERT with a lot columns writing all the placeholders becomes a nightmare:
db.query('INSERT INTO books (name, author, isbn, category, recommended_age, pages, price) VALUES (?, ?, ?, ?, ?, ?, ?)',[name,author,isbn,category,recommendedAge,pages,price])// is better written asdb.query(SQL` INSERT INTO books (name, author, isbn, category, recommended_age, pages, price) VALUES (${name}, ${author}, ${isbn}, ${category}, ${recommendedAge}, ${pages}, ${price})`)Also template strings support line breaks, while normal strings do not.
The SQL template string tag transforms the template string and returns an object that is understood by both mysql and postgres:
constquery=SQL`SELECT author FROM books WHERE name = ${book} AND author = ${author}`typeofquery// => 'object'query.text// => 'SELECT author FROM books WHERE name = $1 AND author = $2'query.sql// => 'SELECT author FROM books WHERE name = ? AND author = ?'query.values// => ['harry potter', 'J. K. Rowling']It is also possible to build queries by appending another query or a string with the append() method (returns this for chaining):
query.append(SQL`AND genre = ${genre}`).append(' ORDER BY rating')query.text// => 'SELECT author FROM books WHERE name = $1 AND author = $2 AND genre = $3 ORDER BY rating'query.sql// => 'SELECT author FROM books WHERE name = ? AND author = ? AND genre = ? ORDER BY rating'query.values// => ['harry potter', 'J. K. Rowling', 'Fantasy'] ORDER BY ratingThis allows you to build complex queries without having to care about the placeholder index or the values array:
constquery=SQL`SELECT * FROM books`if(params.name){query.append(SQL` WHERE name = ${params.name}`)}query.append(SQL` LIMIT 10 OFFSET ${params.offset||0}`)Some values cannot be replaced by placeholders in prepared statements, like table names. append() replaces the SQL.raw() syntax from version 1, just pass a string and it will get appended raw.
Please note that when inserting raw values, you are responsible for quoting and escaping these values with proper escaping functions first if they come from user input (E.g.
mysql.escapeId()andpg.escapeIdentifier()). Also, executing many prepared statements with changing raw values in a loop will quickly overflow the prepared statement buffer (and destroy their performance benefit), so be careful.
consttable='books'constorder='DESC'constcolumn='author'db.query(SQL`SELECT * FROM "`.append(table).append(SQL`" WHERE author = ${author} ORDER BY ${column} `).append(order))// escape user input manuallymysql.query(SQL`SELECT * FROM `.append(mysql.escapeId(someUserInput)).append(SQL` WHERE name = ${book} ORDER BY ${column} `).append(order))pg.query(SQL`SELECT * FROM `.append(pg.escapeIdentifier(someUserInput)).append(SQL` WHERE name = ${book} ORDER BY ${column} `).append(order))To bind the array dynamically as a parameter use ANY (PostgreSQL only):
constauthors=['J. K. Rowling','J. R. R. Tolkien']constquery=SQL`SELECT name FROM books WHERE author = ANY(${authors})`query.text// => 'SELECT name FROM books WHERE author = ANY($1)'query.values// => ['J. K. Rowling', 'J. R. R. Tolkien']Postgres has the option of naming prepared statements, which allows parsing and other work to be reused (and requires the SQL associated with the name to stay the same, with only the parameters changing). You can set the name with the setName() method:
// old waypg.query({name: 'my_query',text: 'SELECT author FROM books WHERE name = $1',values: [book]})// with template stringspg.query(SQL`SELECT author FROM books WHERE name = ${book}`.setName('my_query'))You can also set the name property on the statement object directly or use Object.assign().
By default, Sequelize will escape replacements on the client. To switch to using a bound statement in Sequelize, call useBind(). The boolean parameter defaults to true. Like all methods, returns this for chaining. Please note that as long as the bound mode is active, the statement object only supports Sequelize, not the other drivers.
// old waysequelize.query('SELECT author FROM books WHERE name = ? AND author = ?',{bind: [book,author]})// with template stringssequelize.query(SQL`SELECT author FROM books WHERE name = ${book}`.useBind(true))sequelize.query(SQL`SELECT author FROM books WHERE name = ${book}`.useBind())// the same// works with append (you can call useBind at any time)constquery=SQL`SELECT * FROM books`.useBind(true)if(params.name){query.append(SQL` WHERE name = ${params.name}`)}query.append(SQL` LIMIT 10 OFFSET ${params.offset||0}`)- Sublime Text: javascript-sql-sublime-syntax
- Vim: vim-javascript-sql
- Tests are written using mocha
- You can use
npm testto run the tests and check coding style - Since this module is only compatible with ES6 versions of node anyway, use all the ES6 goodies
- Pull requests are welcome :)