nodejs-mysql-query-generator

• parses optional get parameters of a nodejs get request url and generates a mysql query
• usage e.g. in REST API with extensive optional parameters for filtering

Constructor:

new QueryGenerator(defaultLimit);

For security reasons the construtor allows for providing a default limit value. So if don't ever want to return more than x values, just put it in the constructor. If not, just leave it empty.

provides:

function generateQueryAddition(url)

• takes req.url object and generates a mysql addition query that can be added to a base query

req.url query format

/someUrl?column.modifier=value

column: column to be filtered modifier: type of filtering action value: value to be filtered for

###currently supported query modifiers: modifier => mysql code => example

###general:

• is => "=" => where column = value
• isNot => "!=" => where column != value

###strings only

• contains => "like" => where column like '%value%'
• containsNot => "not like" => where column not like '%value%'
• startsWith => "like value%" => where columne like 'value%'
• endsWith => "like %value" => where columne like '%value'

###numbers only:

• less => "<" => where column < value
• lessOrEqual => "<=" => where column <= value
• greater => ">" => where column > value
• greaterOrEqual => ">=" => where column >= value

illegal (those that are not supported) modifiers will be ignored

###exception ?limit=value limits the returned results to a certain number of entries and doesn't require any modifier

query example:

?name.rocks=7&email.contains=@gmail&id.greater=10&id.lessOrEqual=100&limit=8

would return "where email like '%@gmail%' and id > 10 and id <= 100 limit 8;"

note: name.rocks is an illegal modifier and therefore ignored

usage example:

app.get('/someUrl', function(req, res){
    var QueryGenerator = require('mysql-query-generator');
    var handler = new QueryGenerator(100);
    var queryAddition = handler.generateQueryAddition(req.url);
    var completeQuery = 'select id, username, email from users ' + queryAddition;
});

// assuming a req.url querystring like so: ?username.is=john&email.contains=john.doe&id.greaterOrEqual=10&limit=5
// the complete query would be
var completeQuery = 'select id, username, email from users where name = \'john\' and email like \'%john.doe%\' and id >= 10 limit 5;

Security as of v0.3.0

Injections

To prevent sql injections certain characters and keywords are not allowed like:

• quotes
• whitespaces

Limit number of returned entries

You can provide a default limit in the constructor to make sure no more than that number of entries is returned.

NPM

Check it out at NPM!. npm install mysql-query-generator

Originally intended as an addition to query-sql.

Easily generate simple queries using query-sql. Then automatically parse url get string and add the result as where clause for more extensive filtering.

License

MIT