1
|
|
|
<?php |
2
|
|
|
|
3
|
|
|
/* |
4
|
|
|
* This file is part of YaEtl |
5
|
|
|
* (c) Fabrice de Stefanis / https://github.com/fab2s/YaEtl |
6
|
|
|
* This source file is licensed under the MIT license which you will |
7
|
|
|
* find in the LICENSE file or at https://opensource.org/licenses/MIT |
8
|
|
|
*/ |
9
|
|
|
|
10
|
|
|
namespace fab2s\YaEtl\Extractors; |
11
|
|
|
|
12
|
|
|
use fab2s\NodalFlow\NodalFlowException; |
13
|
|
|
|
14
|
|
|
/** |
15
|
|
|
* abstract Class DbExtractorAbstract |
16
|
|
|
*/ |
17
|
|
|
abstract class DbExtractorAbstract extends ExtractorBatchLimitAbstract |
18
|
|
|
{ |
19
|
|
|
/** |
20
|
|
|
* The SQL query |
21
|
|
|
* |
22
|
|
|
* @var mixed |
23
|
|
|
*/ |
24
|
|
|
protected $extractQuery; |
25
|
|
|
|
26
|
|
|
/** |
27
|
|
|
* @var iterable |
28
|
|
|
*/ |
29
|
|
|
protected $extracted; |
30
|
|
|
|
31
|
|
|
/** |
32
|
|
|
* Instantiate a DB extractor |
33
|
|
|
* |
34
|
|
|
* @param mixed $extractQuery |
35
|
|
|
* |
36
|
|
|
* @throws NodalFlowException |
37
|
|
|
*/ |
38
|
|
|
public function __construct($extractQuery = null) |
39
|
|
|
{ |
40
|
|
|
if ($extractQuery !== null) { |
41
|
|
|
$this->setExtractQuery($extractQuery); |
42
|
|
|
} |
43
|
|
|
|
44
|
|
|
parent::__construct(); |
45
|
|
|
} |
46
|
|
|
|
47
|
|
|
/** |
48
|
|
|
* Trigger a batch extract |
49
|
|
|
* |
50
|
|
|
* @param mixed $param |
51
|
|
|
* |
52
|
|
|
* @return bool |
53
|
|
|
*/ |
54
|
|
|
public function extract($param = null): bool |
55
|
|
|
{ |
56
|
|
|
if ($this->isLimitReached()) { |
57
|
|
|
return false; |
58
|
|
|
} |
59
|
|
|
|
60
|
|
|
$this->enforceBatchSize(); |
61
|
|
|
if ($this->fetchRecords()) { |
62
|
|
|
$this->incrementOffset(); |
63
|
|
|
|
64
|
|
|
return true; |
65
|
|
|
} |
66
|
|
|
|
67
|
|
|
return false; |
68
|
|
|
} |
69
|
|
|
|
70
|
|
|
/** |
71
|
|
|
* Set the Extract SQL query |
72
|
|
|
* |
73
|
|
|
* @param mixed $extractQuery |
74
|
|
|
* |
75
|
|
|
* @return static |
76
|
|
|
*/ |
77
|
|
|
public function setExtractQuery($extractQuery): self |
78
|
|
|
{ |
79
|
|
|
$this->extractQuery = $extractQuery; |
80
|
|
|
|
81
|
|
|
return $this; |
82
|
|
|
} |
83
|
|
|
|
84
|
|
|
/** |
85
|
|
|
* Build the LIMIT...OFFSET bit of the query |
86
|
|
|
* |
87
|
|
|
* @return string |
88
|
|
|
*/ |
89
|
|
|
protected function getLimitOffsetBit(): string |
90
|
|
|
{ |
91
|
|
|
return ' ' . \implode('', [ |
92
|
|
|
' LIMIT ' . (int) $this->batchSize, |
93
|
|
|
$this->offset ? ' OFFSET ' . (int) $this->offset : '', |
94
|
|
|
]); |
95
|
|
|
} |
96
|
|
|
|
97
|
|
|
/** |
98
|
|
|
* Execute query and store results calling this->setExtracted |
99
|
|
|
* |
100
|
|
|
* @return bool true if there are records fetched |
101
|
|
|
*/ |
102
|
|
|
abstract protected function fetchRecords(): bool; |
103
|
|
|
} |
104
|
|
|
|