alasql/src/65createindex.js

AlaSQL.js - JavaScript SQL database library for relational and graph data manipulation with support of localStorage, IndexedDB, and Excel

/*
//
// CREATE TABLE for Alasql.js
// Date: 03.11.2014
// (c) 2014, Andrey Gershun
//
*/

yy.CreateIndex = function (params) { return yy.extend(this, params); }
yy.CreateIndex.prototype.toString = function() {
	var s = 'CREATE';
	if(this.unique) s+=' UNIQUE';
	s += ' INDEX ' + this.indexid + " ON "+this.table.toString();
	s += "("+this.columns.toString()+")";
	return s;
}

// CREATE TABLE
yy.CreateIndex.prototype.execute = function (databaseid,params,cb) {
//	var self = this;
	var db = alasql.databases[databaseid];
	var tableid = this.table.tableid;
	var table = db.tables[tableid];
	var indexid = this.indexid;

	if(this.unique) {
		var rightfns = this.columns.map(function(colid){return "r[\'"+colid+"\']"}).join("+'`'+");
		table.uniqdefs[indexid] = {
			rightfns: rightfns
		};
		var ux = table.uniqs[indexid] = {};
		if(table.data.length > 0) {
			for(var i=0, ilen=table.data.length; i<ilen;i++) {
				var addr = rightfns(table.data[i]);
				if(!ux[addr]) {
					ux[addr] = {num:0};
				};
				ux[addr].num++;
			}
		}
	} else {
		var rightfns = this.columns.map(function(colid){return "r[\'"+colid+"\']"}).join("+'`'+");
		var hh = hash(rightfns);
		table.inddefs[indexid] = {rightfns:rightfns, hh:hh};
		table.indices[hh] = {};

		var ix = table.indices[hh] = {};
		if(table.data.length > 0) {
			for(var i=0, ilen=table.data.length; i<ilen;i++) {
				var addr = rightfns(table.data[i]);
				if(!ix[addr]) {
					ix[addr] = [];
				};
				ix[addr].push(table.data[i]);
			}
		}
	};
	var res = 1;
	if(cb) res = cb(res);
	return res;
};