node-query/lib/driver.js

159 lines
3.2 KiB
JavaScript
Executable File

'use strict';
var helpers = require('./helpers');
/**
* Base Database Driver
*
* @module driver
*/
var d = {
identifierChar: '"',
tablePrefix: null,
hasTruncate: true,
/**
* Low level function for naive quoting of strings
* @param {String} str
* @return {String}
* @private
*/
_quote: function(str) {
return (helpers.isString(str) && ! (str.startsWith(d.identifierChar) || str.endsWith(d.identifierChar)))
? d.identifierChar + str + d.identifierChar
: str;
},
/**
* Set the limit clause
* @param {String} sql
* @param {Number} limit
* @param {Number|null} offset
* @return {String}
*/
limit: function(sql, limit, offset) {
sql += " LIMIT " + limit;
if (helpers.isNumber(offset))
{
sql += " OFFSET " + offset;
}
return sql;
},
/**
* Quote database table name, and set prefix
*
* @param {String} table
* @return {String}
*/
quoteTable: function(table) {
// Quote after prefix
return d.quoteIdentifiers(table);
},
/**
* Use the driver's escape character to quote identifiers
*
* @param {String|Array}
* @return {String|Array}
*/
quoteIdentifiers: function(str) {
var hiers, raw;
var pattern = new RegExp(d.identifierChar + '(' + '([a-zA-Z0-9_]+)' + '(\((.*?)\))' + ')' + d.identifierChar, 'ig');
// Recurse for arrays of identifiiers
if (Array.isArray(str))
{
return str.map(d.quoteIdentifiers);
}
// Handle commas
if (str.includes(','))
{
var parts = str.split(',').map(helpers.stringTrim);
str = parts.map(d.quoteIdentifiers).join(',');
}
// Split identifiers by period
hiers = str.split('.').map(d._quote);
raw = hiers.join('.');
// Fix functions
if (raw.includes('(') && raw.includes(')'))
{
var funcs = pattern.exec(raw);
// Unquote the function
raw = raw.replace(funcs[0], funcs[1]);
// Quote the identifiers inside of the parens
var inParens = funcs[3].substring(1, funcs[3].length -1);
raw = raw.replace(inParens, d.quoteIdentifiers(inParens));
}
return raw;
},
/**
* SQL to truncate the passed table
*
* @param {String} table
* @return {String} - sql
*/
truncate: function(table) {
var sql = (d.hasTruncate)
? 'TRUNCATE '
: 'DELETE FROM ';
sql += d.quoteTable(table);
return sql;
},
/**
* SQL to insert a group of rows
*
* @param {String} table - The table to insert to
* @param {Array} [data] - The array of object containing data to insert
* @return {String}
*/
insertBatch: function(table, data) {
// Get the data values to insert, so they can
// be parameterized
var vals = [];
data.forEach(function(obj) {
Object.keys(obj).forEach(function(key) {
vals.push(obj[key]);
});
});
// Get the field names from the keys of the first
// object inserted
var fields = Object.keys(data[0]);
table = d.quoteTable(table);
var sql = "INSERT INTO " + table + " ("
+ d.quoteIdentifiers(fields).join(",")
+ ") VALUES ";
// Create placeholder groups
var params = new Array(fields.length).fill('?');
var paramString = "(" + params.join(',') + ")";
var paramList = new Array(data.length).fill(paramString);
sql += paramList.join(',');
return {
sql: sql,
values: vals
};
}
};
module.exports = d;