CQL query generator in node.js

cql_constructor.js

var _ = require('underscore');

var cassandra = function(client) {
    var that = this;
    that.__query__ = "";
    that.__error__ = false;
    that.__q__ = null;

    return that;
};

cassandra.prototype.select = function() {
    var args = Array.prototype.slice.call(arguments);
    var that = this;

    that.__q__ = "SELECT";
    that.__query__ += " SELECT ";

    if (args.length) {
        args.forEach(function(arg){ that.__query__ += (" " + arg + ",") });
        console.log()
        that.__query__ = that.__query__.slice(0, -1); // chop off the last comma
    }
    return that;
};

cassandra.prototype.from = function() {
    var that = this;
    var args = Array.prototype.slice.call(arguments);

    if (!args.length) that.__error__ = that.__q__;

    that.__q__ = "FROM";
    that.__query__ += " FROM ";
    that.__query__ += arguments[0];
    return that;
};

cassandra.prototype.where = function(condition) {
    var that = this;
    if (!condition) that.__error__ = that.__q__;

    that.__q__ = "WHERE";
    that.__query__ += " WHERE ";
    that.__query__ += condition;
    return that;
};

cassandra.prototype.and = function(condition) {
    var that = this;
    if (!condition) that.__error__ = that.__q__;

    if (that.__q__ === "WHERE" || that.__q__ === "USING" || that.__q__ === "IF")
        that.__query__ += " AND ";
    else that.__query__ += ", ";

    that.__query__ += condition;
    return that;
};

cassandra.prototype.or = function(condition) {
    var that = this;
    if (!condition) that.__error__ = that.__q__;

    if (that.__q__ === "WHERE") that.__query__ += " OR ";
    else that.__query__ += ", ";

    that.__query__ += condition;
    return that;
};

cassandra.prototype.orderBy = function(arg) {
    var that = this;
    if (!arg) that.__error__ = that.__q__;
    that.__q__ = "ORDER BY";

    that.__query__ += " ORDER BY " + arg;
    return that;
};

cassandra.prototype.desc = function() {
    var that = this;
    that.__query__ += " DESC ";
    return that;
};

cassandra.prototype.asc = function() {
    var that = this;
    that.__query__ += " ASC ";
    return that;
};

cassandra.prototype.distinct = function() {
    var that = this;
    that.__q__ = "DISTINCT";
    that.__query__ += " DISTINCT ";
    return that;
};

cassandra.prototype.limit = function(entries) {
    var that = this;
    if (!entries) entries = 10; // should we set a default?
    that.__q__ = "LIMIT";

    that.__query__ += " LIMIT ";
    that.__query__ += entries;
    return that;
};

cassandra.prototype.insertInto = function(into) {
    var that = this;
    if (!into) that.__error__ = false;
    that.__q__ = "INSERT";

    that.__query__ += " INSERT INTO ";
    that.__query__ += into;
    return that;
};

cassandra.prototype.values = function(values) {
    var that = this;
    if (!values) that.__error__ = that.__q__;
    that.__q__ = "VALUES";

    var columns = " (";
    var columnValues = " (";
    Object.keys(values).forEach(function(k) {
        columns += k + ", ";
        columnValues += values[k] + ", ";
    });
    columns = columns.slice(0, -2); // remove the trailing comma
    columns += ") ";
    columnValues = columnValues.slice(0, -2);
    columnValues += ") ";

    that.__query__ += columns + " VALUES " + columnValues;
    return that;
};

cassandra.prototype.using = function(option, value) {
    var that = this;
    if (!option || !value) that.__error__ = that.__q__;
    that.__q__ = "USING";

    if (option === "ttl")
        that.__query__ += " USING TTL " + value;
    else if (option === "timestamp")
        that.__query__ += " USING TIMESTAMP " + value;
    return that;
};

cassandra.prototype.update = function(table) {
    var that = this;
    if (!table) that.__error__ = that.__q__;
    that.__q__ = "UPDATE";

    that.__query__ += " UPDATE " + table;
    return that;
};

cassandra.prototype.set = function(values) {
    var that = this;
    if (!values || !_.isObject(values)) that.__error__ = that.__q__;
    that.__q__ = "SET";

    that.__query__ += " SET ";
    Object.keys(values).forEach(function(k) {
        that.__query__ += (k + "=" + values[k]);
        that.__query__ += ", ";
    });
    that.__query__ = that.__query__.slice(0, -2); // remove trailing space and comma
    return that;
};

cassandra.prototype.if = function(condition) {
    var that = this;
    if (!condition) that.__error__ = that.__q__;
    that.__q__ = "IF";

    that.__query__ += " IF ";
    that.__query__ += condition;
};


c =  new cassandra();
c.select("col1", "col2")
    .from("table1")
    .where("col3 > 10")
    .and("col4 < 10")
    .and("col5 = 5")
    .orderBy("col6").asc()
    .distinct()
    .limit(100)
;
console.log(c);

d = new cassandra();
d.insertInto("table1")
    .values({
        col1: 1,
        col2: 2,
        col3: "haha"
    })
    .using("ttl", 60000)
;
console.log(d);

e = new cassandra();
e.update("table1")
    .using("ttl", 60000)
    .set({
        col1: 1,
        col2: 2,
        col3: 3
    })
    .where("col4 > 5")
    .and("col5 > 6")
    .and("col7 > 8")
    .if("col8 = 1")
;
console.log(e);