aql-postgres

Uitilities to run AQL queries on postgres databases. Currently it only supports building the condition part of the query.

More information about AQL can be found in the spec.

Note that this utility builds raw SQL strings based on your input. You can provide a context object that implements escapeKey(key), escapeValue(value) and escapeList(list) functions if you need some parts of the condition to be escaped.

Usage

npm install --save @ambassify/aql-postgres

const pgAQL = require('@ambassify/aql-postgres');

const condition = {
    operator: 'and',
    value: [
        { key: 'e.type', operator: 'in', value: [ 'video', 'image' ] },
        { key: 'e.likes', operator: 'gte', value: 10 },
    ]
};

/**
 * You need to provide a context object that has methods to escape values
 * to make them safe for use in SQL. The easiest way to do this is by using
 * parameters in your query. Knex allows named parameters for example. This
 * example shows you how it could be done.
 */
const context = {
    parameters: {},
    escapeKey(key) {
        return `${context.escapeValue(key)}:`;
    },
    escapeValue(value) {
        const name = `param_${Object.keys(context.parameters).length}`;
        context.parameters[name] = value;
        return `:${name}`;
    },
    escapeList(value) {
        return value.map(v => context.escapeValue(v)).join(',');
    }
};

const query = `
    SELECT *
    FROM engagement e
    WHERE ${pgAQL.condition(condition, context)}
`;

// use your favorite driver to execute the query
const results = await knex().raw(query, context.parameters);