|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
namespace mindplay\sql\framework; |
|
4
|
|
|
|
|
5
|
|
|
use Iterator; |
|
6
|
|
|
use IteratorAggregate; |
|
7
|
|
|
use RuntimeException; |
|
8
|
|
|
use Traversable; |
|
9
|
|
|
|
|
10
|
|
|
/** |
|
11
|
|
|
* This class represents the result of fetching a `PreparedStatement`, e.g. the results of |
|
12
|
|
|
* a `SELECT` SQL query, and with Mappers being applied on-the-fly, in batches. |
|
13
|
|
|
* |
|
14
|
|
|
* It implements `IteratorAggregate`, allowing you to execute the query and iterate |
|
15
|
|
|
* over the result set with a `foreach` statement. |
|
16
|
|
|
* |
|
17
|
|
|
* @implements IteratorAggregate<array<string,mixed>> |
|
18
|
|
|
*/ |
|
19
|
|
|
class Result implements IteratorAggregate |
|
20
|
|
|
{ |
|
21
|
|
|
private PreparedStatement $statement; |
|
22
|
|
|
private int $batch_size; |
|
23
|
|
|
|
|
24
|
|
|
/** |
|
25
|
|
|
* @var Mapper[] list of Mappers to apply when fetching results |
|
26
|
|
|
*/ |
|
27
|
|
|
private array $mappers; |
|
28
|
|
|
|
|
29
|
|
|
/** |
|
30
|
|
|
* @param PreparedStatement $statement prepared statement |
|
31
|
|
|
* @param int $batch_size batch-size (when fetching large result sets) |
|
32
|
|
|
* @param Mapper[] $mappers list of Mappers to apply while fetching results |
|
33
|
|
|
*/ |
|
34
|
1 |
|
public function __construct(PreparedStatement $statement, int $batch_size, array $mappers) |
|
35
|
|
|
{ |
|
36
|
1 |
|
$this->statement = $statement; |
|
37
|
1 |
|
$this->batch_size = $batch_size; |
|
38
|
1 |
|
$this->mappers = $mappers; |
|
39
|
|
|
} |
|
40
|
|
|
|
|
41
|
|
|
/** |
|
42
|
|
|
* @return array<string,mixed>|null first record of the record-set (or NULL, if the record-set is empty) |
|
43
|
|
|
*/ |
|
44
|
1 |
|
public function firstRow(): array|null |
|
45
|
|
|
{ |
|
46
|
1 |
|
foreach ($this->createIterator(1) as $record) { |
|
47
|
1 |
|
return $record; // break from loop immediately after fetching the first record |
|
48
|
|
|
} |
|
49
|
|
|
|
|
50
|
|
|
return null; |
|
51
|
|
|
} |
|
52
|
|
|
|
|
53
|
|
|
/** |
|
54
|
|
|
* @return mixed|null first column value of the first record of the record-set (or NULL, if the record-set is empty) |
|
55
|
|
|
*/ |
|
56
|
1 |
|
public function firstCol(): mixed |
|
57
|
|
|
{ |
|
58
|
1 |
|
foreach ($this->createIterator(1) as $record) { |
|
59
|
1 |
|
$keys = array_keys($record); |
|
60
|
|
|
|
|
61
|
1 |
|
return $record[$keys[0]]; // break from loop immediately after fetching the first record |
|
62
|
|
|
} |
|
63
|
|
|
|
|
64
|
|
|
return null; |
|
65
|
|
|
} |
|
66
|
|
|
|
|
67
|
|
|
/** |
|
68
|
|
|
* @return array<array<string,mixed>> all the records of the record-set |
|
69
|
|
|
*/ |
|
70
|
1 |
|
public function all(): array |
|
71
|
|
|
{ |
|
72
|
1 |
|
return iterator_to_array($this->getIterator()); |
|
73
|
|
|
} |
|
74
|
|
|
|
|
75
|
|
|
/** |
|
76
|
|
|
* Execute this Statement and return a Generator, so you can iterate over the results. |
|
77
|
|
|
* |
|
78
|
|
|
* This method implements `IteratorAggregate`, permitting you to iterate directly over |
|
79
|
|
|
* the resulting records (or objects) without explicitly having to call this method. |
|
80
|
|
|
*/ |
|
81
|
1 |
|
public function getIterator(): Traversable |
|
82
|
|
|
{ |
|
83
|
1 |
|
return $this->createIterator($this->batch_size); |
|
84
|
|
|
} |
|
85
|
|
|
|
|
86
|
|
|
/** |
|
87
|
|
|
* Create an Iterator with a given batch-size. |
|
88
|
|
|
* |
|
89
|
|
|
* @param int $batch_size batch-size when processing the result set |
|
90
|
|
|
* |
|
91
|
|
|
* @return Iterator |
|
92
|
|
|
*/ |
|
93
|
1 |
|
private function createIterator($batch_size): Iterator |
|
94
|
|
|
{ |
|
95
|
1 |
|
$fetching = true; |
|
96
|
|
|
|
|
97
|
1 |
|
$record_index = 0; |
|
98
|
|
|
|
|
99
|
|
|
do { |
|
100
|
|
|
// fetch a batch of records: |
|
101
|
|
|
|
|
102
|
1 |
|
$batch = []; |
|
103
|
|
|
|
|
104
|
|
|
do { |
|
105
|
1 |
|
$record = $this->statement->fetch(); |
|
106
|
|
|
|
|
107
|
1 |
|
if ($record) { |
|
108
|
1 |
|
$batch[$record_index++] = $record; |
|
109
|
|
|
} else { |
|
110
|
1 |
|
if (count($batch) === 0) { |
|
111
|
1 |
|
return; // last batch of records fetched |
|
112
|
|
|
} |
|
113
|
|
|
|
|
114
|
1 |
|
$fetching = false; // last record of batch fetched |
|
115
|
|
|
} |
|
116
|
1 |
|
} while ($fetching && (count($batch) < $batch_size)); |
|
117
|
|
|
|
|
118
|
|
|
// apply Mappers to current batch of records: |
|
119
|
|
|
|
|
120
|
1 |
|
$num_records = count($batch); |
|
121
|
|
|
|
|
122
|
1 |
|
foreach ($this->mappers as $mapper_index => $mapper) { |
|
123
|
1 |
|
$batch = $mapper->map($batch); |
|
124
|
|
|
|
|
125
|
1 |
|
if ($batch instanceof Traversable) { |
|
126
|
1 |
|
$batch = iterator_to_array($batch); |
|
127
|
|
|
} |
|
128
|
|
|
|
|
129
|
1 |
|
if (count($batch) !== $num_records) { |
|
130
|
|
|
$count = count($batch); |
|
131
|
|
|
|
|
132
|
|
|
throw new RuntimeException("Mapper #{$mapper_index} returned {$count} records, expected: {$num_records}"); |
|
133
|
|
|
} |
|
134
|
|
|
} |
|
135
|
|
|
|
|
136
|
|
|
// return each record from the current batch: |
|
137
|
|
|
|
|
138
|
1 |
|
foreach ($batch as $index => $record) { |
|
139
|
1 |
|
yield $index => $record; |
|
140
|
|
|
} |
|
141
|
1 |
|
} while ($fetching); |
|
142
|
|
|
} |
|
143
|
|
|
} |
|
144
|
|
|
|
mindplay-dk /
sql
