-
Notifications
You must be signed in to change notification settings - Fork 8
/
crud.js
485 lines (425 loc) · 15.8 KB
/
crud.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
var TableRegistry = require('./tableRegistry'),
Util = require('./util'),
Table = require('./table'),
Join = require('./join');
var CRUD = function(driver, table, options) {
options = options || {};
this.driver = driver;
this.table = TableRegistry.getTableDefinition(table) || {};
this.selectColumns = options.selectColumns || this.table.selectColumns;
this.columns = options.columns || this.table.columns;
this.tableName = table;
this.defaultSelectCriteria = options.defaultSelectCriteria || table.defaultSelectCriteria;
this.load = options.load;
this.id = options.id || this.table.id || 'id';
this.logger = options.logger || console.log;
this.columnMap = this.table.columnMap;
this.defaultJoins = this.table.defaultJoins;
};
/*
* query - execute an SQL query
*
* query: the text of the query; can be parameterized with placeholders $1, $2, etc
* parameters: an array of values for each of the placeholders in the query
* callback: a function with signature (err, result) to be called with results of the query
*/
CRUD.prototype.query = function(query, parameters, callback) {
this.driver.query(query, parameters, "SQL QUERY", callback);
};
/*
* findMany - execute a SELECT and return many rows
*
* options:
* criteria: filter criteria that are applied to the WHERE clause to limit results
* columns: array of column names to return
* joins: array of join names to apply to the query
* limit: (int) max number of rows
* offset: (int) start row
* sort: hash of column names mapped to ASC or DESC
* callback: a function with signature (err, result) to be called with results of the query
*/
CRUD.prototype.findMany = function(options, callback) {
var values = [],
query,
self = this;
options = options || {};
if (this.defaultSelectCriteria)
options.criteria = Util.extend({}, this.defaultSelectCriteria, options.criteria);
query = 'SELECT ' + this.table.selectColumnList(options.columns || this.selectColumns, options.joins) + ' FROM ' + this.tableName;
query += this._applyJoins(options.joins);
query += this._applyCriteria(options, values);
if (typeof(callback) !== 'function')
callback = CRUD.returnMany(callback);
if (this.table.needsJoinPostProcessing(options.joins))
callback = this._createJoinCallback(options, callback);
this.driver.query(query, values, this.tableName, callback);
};
/*
* findById - execute a SELECT using the table's unique id column and return one row
*
* id: the value of the id
* callback: a function with signature (err, result) to be called with results of the query
*/
CRUD.prototype.findById = function(id, callback) {
var criteria = {};
criteria[this.id] = id;
return this.findOne({ criteria: criteria }, callback);
};
/*
* findOne - execute a SELECT with criteria and return the first row
* options: (same as findMany)
* callback: a function with signature (err, result) to be called with results of the query
*/
CRUD.prototype.findOne = function(options, callback) {
var values = [],
query;
options = options || {};
query = 'SELECT ' + this.table.selectColumnList(options.columns || this.selectColumns, options.joins) + ' FROM ' + this.tableName;
query += this._applyJoins(options.joins);
query += this._applyCriteria(options, values);
callback = CRUD.returnOne(callback);
this.driver.query(query, values, this.tableName, callback);
};
/*
* create - execute an INSERT and return the id of the new row
*
* options:
* data: a hash that maps column names to column values
* callback: a function with signature (err, result) to be called with results of the query
*/
CRUD.prototype.create = function(options, callback) {
var values = [],
column,
self = this,
data = options.data;
var columns = this.columns.filter(function(col) {
return col !== this.id;
}, this);
var columnList = columns.map(function(item) { return this.columnMap[item]; }, this);
var query = 'INSERT INTO ' + this.tableName
+ ' ( ' + columnList + ' ) '
+ ' VALUES ( ';
for (var i = 0; i < columns.length; i++) {
column = columns[i];
if (column === 'createdAt')
values[i] = new Date();
else if (column === 'updatedAt')
values[i] = new Date();
else
values[i] = data[column];
query += '$' + (i + 1);
if (i < columns.length - 1)
query += ', ';
}
query += ') ';
query += options.returning || this.driver.getInsertQueryText(this.table);
if (typeof(callback) !== 'function')
callback = CRUD.returnOne(callback);
this.driver.query(query, values, this.tableName, function(err, result) {
var id = self.driver.getIdForInsert(self.table, result);
var obj = {};
obj[self.id] = id;
callback(err, obj);
});
};
/*
* update - execute an UPDATE statement
*
* options:
* criteria: (same as findMany)
* data: a hash that maps column names to column values
* callback: a function with signature (err, result) to be called with results of the query
*/
CRUD.prototype.update = function(options, callback) {
var values = [],
column,
data,
j = 0,
columns = this.columns,
query = 'UPDATE ' + this.tableName + ' SET ';
options = options || {};
data = options.data;
for (var i = 0; i < columns.length; i++) {
column = columns[i];
if (column === 'createdAt') {
continue;
} else if (column === 'updatedAt') {
values[j++] = new Date();
query += this.columnMap[column] + ' = $' + j + ', ';
} else if (column in data) {
values[j++] = data[column];
query += this.columnMap[column] + ' = $' + j + ', ';
}
}
// remove trailing comma and space
query = query.substr(0, query.length - 2);
if (typeof(callback) !== 'function')
callback = CRUD.returnResult(callback);
query += this._applyCriteria(options, values);
this.driver.query(query, values, this.tableName, callback);
};
/*
* remove - execute a DELETE statement to remove all rows that match the criteria
*
* optionsOrId:
* criteria - (same as findMany)
* callback: a function with signature (err, result) to be called with results of the query
*/
CRUD.prototype.remove = function(optionsOrId, callback) {
var values = [],
query = 'DELETE FROM ' + this.tableName;
if (optionsOrId && (typeof optionsOrId === 'object')) {
query += this._applyCriteria(optionsOrId, values);
} else if (optionsOrId) {
// we were passed the row id directly
query += ' WHERE ' + this.id + ' = $1';
values[0] = optionsOrId;
}
if (typeof(callback) !== 'function')
callback = CRUD.returnResult(callback);
this.driver.query(query, values, this.tableName, callback);
};
CRUD.prototype._applyJoins = function(additionalJoins) {
var query = "",
joins = this.defaultJoins;
if (additionalJoins)
joins = joins.concat(additionalJoins);
joins.forEach(function(joinName) {
var join = this.table.joins[joinName];
if (join)
query += this._join(join);
else
this.logger('Table ' + this.tableName + ' is missing a join named ' + joinName);
}, this);
return query;
};
// build a join clause
CRUD.prototype._join = function(criteria) {
var query = ' LEFT OUTER JOIN ' + criteria.table + ' ON ',
childTable = TableRegistry.getTableDefinition(criteria.table),
onClauses = [],
self = this;
Util.eachKey(criteria.criteria, function(parentCol, childCol) {
onClauses.push(self.tableName + '.' + self.columnMap[parentCol]
+ ' = ' + criteria.table + '.' + childTable.columnMap[childCol]);
});
query += onClauses.join(', ');
return query;
};
CRUD.prototype.selectColumnList = function(dbColumns, joinOrPrefix) {
return this.table.selectColumnList(dbColumns, joinOrPrefix);
};
/*
* _applyCriteria - create WHERE, ORDER BY, and LIMIT clauses for the query
* options:
* criteria: filter criteria that are applied to the WHERE clause to limit results
* columns: array of column names to return
* joins: array of join names to apply to the query
* limit: (int) max number of rows
* offset: (int) start row
* sort: hash of column names mapped to ASC or DESC
* values - an array of parameter values
*/
CRUD.prototype._applyCriteria = function(options, values) {
var i = values.length + 1,
prefix = ' ',
query = '',
whereClauses = [],
self = this;
if ((self.defaultJoins.length > 0) || options.joins)
prefix = ' ' + this.tableName + '.';
if (options.criteria) {
Util.eachKey(options.criteria, function(column, value) {
if (value == null) {
whereClauses.push(prefix + self.columnMap[column] + ' IS NULL ');
} else if (typeof(value) === 'object') {
var keys = Object.keys(value);
var operator;
switch (keys[0]) {
case 'lt':
case 'LT': operator = '<'; break;
case 'lte':
case 'LTE': operator = '<='; break;
case 'gt':
case 'GT': operator = '>'; break;
case 'gte':
case 'GTE': operator = '>='; break;
case 'ne':
case 'NE': operator = '<>'; break;
case 'between':
case 'BETWEEN': operator = 'B'; break;
case 'like':
case 'LIKE': operator = 'LIKE'; break;
case 'ilike':
case 'ILIKE': operator = 'ILIKE'; break;
}
if (operator) {
if (operator === 'B') {
whereClauses.push(prefix + self.columnMap[column] + ' >= $' + i++);
values.push(value[keys[0]][0]);
whereClauses.push(prefix + self.columnMap[column] + ' < $' + i++);
values.push(value[keys[0]][1]);
} else if ((operator === '<>') && (value[keys[0]] === null)) {
whereClauses.push(prefix + self.columnMap[column] + ' IS NOT NULL ');
} else {
whereClauses.push(prefix + self.columnMap[column] + ' ' + operator + ' $' + i++);
values.push(value[keys[0]]);
}
} else {
self.logger("ERROR");
}
} else {
whereClauses.push(prefix + self.columnMap[column] + ' = $' + i++);
values.push(value);
}
});
if (whereClauses.length > 0)
query += ' WHERE ' + whereClauses.join(' AND ');
}
if (options.sort) {
query += ' ORDER BY ';
Util.eachKey(options.sort, function(column, direction) {
direction = (direction === "DESC") ? "DESC" : "ASC";
query += prefix + self.columnMap[column] + ' ' + direction;
});
}
if (options.limit)
query += ' LIMIT ' + parseInt(options.limit);
if (options.offset)
query += ' OFFSET ' + parseInt(options.offset);
return query;
};
/*
* create a callback the will postprocess the result rows by creating sub objects for each
* one-to-many join
*/
CRUD.prototype._createJoinCallback = function (options, callback) {
var joinNames = this.defaultJoins;
var joins = [];
var idColumn = this.id;
var self = this;
if (options.joins)
joinNames = joinNames.concat(options.joins);
for (var i = 0; i < joinNames.length; i++) {
var join = this.table.joins[joinNames[i]];
if (join.type === Join.ONE_TO_MANY) {
var map = join.map;
var joinTable = TableRegistry.getTableDefinition(join.table);
if (!map)
map = joinTable.columnMap;
joins.push({
name:join.table,
columns:Object.keys(map)
});
}
}
return function (err, result) {
var resultHash = new OrderedHash();
if (err || !result) {
callback(err, result);
return;
}
for (var r = 0; r < result.rows.length; r++) {
var row = result.rows[r];
// if the index column has changed, create a new row
var currentRow = resultHash.get(row[idColumn]);
if (!currentRow) {
currentRow = {};
resultHash.put(row[idColumn], currentRow);
var keys = Object.keys(row);
for (var k = 0; k < keys.length; k++) {
if (keys[k].indexOf('.') === -1)
currentRow[keys[k]] = row[keys[k]];
}
}
// for each join, move the join data into a child object of the current row
for (var j = 0; j < joins.length; j++) {
var join = joins[j];
var data = {};
var columns = join.columns;
if (!currentRow[join.name])
currentRow[join.name] = [];
var haveData = false;
for (var c = 0; c < columns.length; c++) {
var name = join.name + '.' + columns[c];
if (row[name]) {
data[columns[c]] = row[name];
haveData = true;
}
delete row[name];
}
if (haveData)
currentRow[join.name].push(data);
}
}
self.logger('\n\tconverted to ' + JSON.stringify(resultHash.items));
callback(err, { rows:resultHash.items, rowCount:resultHash.items.length });
};
};
// static methods
// remove null values; should this be an option?
CRUD.clean = function(object) {
if (Array.isArray(object)) {
for (var i = 0; i < object.length; i++)
CRUD.clean(object[i]);
}
for (var attr in object) {
if (object.hasOwnProperty(attr)) {
if (object[attr] == null)
delete object[attr];
}
}
};
CRUD.returnMany = function(response) {
return function (err, result) {
if (err) {
response.send('[ database error: ' + err + ']', 500);
} else {
CRUD.clean(result.rows);
response.send(result.rows);
}
}
};
CRUD.returnOne = function(response) {
return function(err, result) {
if (err) {
if (response.send)
response.send('[ database error: ' + err + ']', 500);
else if (typeof response === "function")
response(err, result);
} else {
if (response.send) {
CRUD.clean(result.rows[0]);
response.send(result.rows[0]);
} else if (typeof response === "function") {
if (result.rows)
response(null, result.rows[0]);
else
response(null, result);
}
}
}
};
CRUD.returnResult = function(response) {
return function(err, result) {
if (err) {
response.send('[ database error: ' + err + ']', 500);
} else {
response.send(result.rows);
}
}
};
// implementation of a hash table that preserves the order that the items were added
function OrderedHash() {
this.items = [];
this.hash = {};
}
OrderedHash.prototype.get = function (key) {
return this.hash[key];
};
// this 'put' is not very robust, but is sufficient for our needs
OrderedHash.prototype.put = function (key, value) {
this.items.push(value);
this.hash[key] = value;
};
module.exports = CRUD;