Add table specific LIMITs

ifsnop · Feb 17, 2019 · 9d131c2 · 9d131c2
1 parent c1af684
commit 9d131c2
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diff --git a/README.md b/README.md
@@ -117,6 +117,19 @@ $dumper->setTableWheres(array(
 ));
 ```
 
+## Table specific export limits
+You can register table specific 'limits' to limit the returned rows on a per table basis:
+
+```php
+$dumper = new IMysqldump\Mysqldump('mysql:host=localhost;dbname=testdb', 'username', 'password');
+
+$dumper->setTableLimits(array(
+    'users' => 300,
+    'logs' => 50,
+    'posts' => 10
+));
+```
+
 ## Constructor and default parameters
 ```php
 /**

diff --git a/src/Ifsnop/Mysqldump/Mysqldump.php b/src/Ifsnop/Mysqldump/Mysqldump.php
@@ -105,6 +105,7 @@ class Mysqldump
      * @var array
      */
     private $tableWheres = array();
+    private $tableLimits = array();
 
     /**
      * Constructor of Mysqldump. Note that in the case of an SQLite database
@@ -258,6 +259,36 @@ public function getTableWhere($tableName)
         return false;
     }
 
+    /**
+     * Keyed by table name, with the value as the numeric limit:
+     * e.g. 'users' => 3000
+     *
+     * @param array $tableLimits
+     */
+    public function setTableLimits(array $tableLimits)
+    {
+        $this->tableLimits = $tableLimits;
+    }
+
+    /**
+     * Returns the LIMIT for the table.  Must be numeric to be returned.
+     * @param $tableName
+     * @return bool
+     */
+    public function getTableLimit($tableName)
+    {
+        if (empty($this->tableLimits[$tableName])) {
+            return false;
+        }
+
+        $limit = $this->tableLimits[$tableName];
+        if (!is_numeric($limit)) {
+            return false;
+        }
+
+        return $limit;
+    }
+
     /**
      * Parse DSN string and extract dbname value
      * Several examples of a DSN string
@@ -1019,6 +1050,12 @@ private function listValues($tableName)
             $stmt .= " WHERE {$condition}";
         }
 
+        $limit = $this->getTableLimit($tableName);
+
+        if ($limit) {
+            $stmt .= " LIMIT {$limit}";
+        }
+
         $resultSet = $this->dbHandler->query($stmt);
         $resultSet->setFetchMode(PDO::FETCH_ASSOC);
 

diff --git a/unit-tests/MysqldumpTest.php b/unit-tests/MysqldumpTest.php
@@ -28,4 +28,21 @@ public function tableSpecificWhereConditionsWork()
             $dump->getTableWhere('non_overriden_table')
         );
     }
+
+    /** @test */
+    public function tableSpecificLimitsWork()
+    {
+        $dump = new Mysqldump('mysql:host=localhost;dbname=test', 'testing', 'testing');
+
+        $dump->setTableLimits(array(
+            'users' => 200,
+            'logs' => 500,
+            'table_with_invalid_limit' => '41923, 42992'
+        ));
+
+        $this->assertEquals(200, $dump->getTableLimit('users'));
+        $this->assertEquals(500, $dump->getTableLimit('logs'));
+        $this->assertFalse($dump->getTableLimit('table_with_invalid_limit'));
+        $this->assertFalse($dump->getTableLimit('table_name_with_no_limit'));
+    }
 }