Initial SQLite development (#1)

Reviewed-on: #1

src/Count.php

@@ -0,0 +1,39 @@
+<?php declare(strict_types=1);
+
+namespace BitBadger\PDODocument;
+
+use BitBadger\PDODocument\Mapper\CountMapper;
+
+/**
+ * Functions to count documents
+ */
+class Count
+{
+    /**
+     * Count all documents in a table
+     *
+     * @param string $tableName The name of the table in which documents should be counted
+     * @return int The count of documents in the table
+     * @throws DocumentException If one is encountered
+     */
+    public static function all(string $tableName): int
+    {
+        return Custom::scalar(Query\Count::all($tableName), [], new CountMapper());
+    }
+
+    /**
+     * Count matching documents using a comparison on JSON fields
+     *
+     * @param string $tableName The name of the table in which documents should be counted
+     * @param array|Field[] $fields The field comparison to match
+     * @param string $conjunction How to handle multiple conditions (optional; defaults to `AND`)
+     * @return int The count of documents matching the field comparison
+     * @throws DocumentException If one is encountered
+     */
+    public static function byFields(string $tableName, array $fields, string $conjunction = 'AND'): int
+    {
+        $namedFields = Parameters::nameFields($fields);
+        return Custom::scalar(Query\Count::byFields($tableName, $namedFields, $conjunction),
+            Parameters::addFields($namedFields, []), new CountMapper());
+    }
+}