Initial SQLite development (#1)

Reviewed-on: #1

src/Query/Patch.php

@@ -0,0 +1,55 @@
+<?php declare(strict_types=1);
+
+namespace BitBadger\PDODocument\Query;
+
+use BitBadger\PDODocument\{Configuration, DocumentException, Field, Mode, Query};
+
+/**
+ * Queries to perform partial updates on documents
+ */
+class Patch
+{
+    /**
+     * Create an UPDATE statement to patch documents
+     *
+     * @param string $tableName The name of the table in which documents should be patched
+     * @param string $whereClause The body of the WHERE clause to use in the UPDATE statement
+     * @return string The UPDATE statement to perform the patch
+     * @throws DocumentException If the database mode has not been set
+     */
+    public static function update(string $tableName, string $whereClause): string
+    {
+        $setValue = match (Configuration::$mode) {
+            Mode::PgSQL  => 'data || :data',
+            Mode::SQLite => 'json_patch(data, json(:data))',
+            default      => throw new DocumentException('Database mode not set; cannot make patch statement')
+        };
+        return "UPDATE $tableName SET data = $setValue WHERE $whereClause";
+    }
+
+    /**
+     * Query to patch (partially update) a document by its ID
+     *
+     * @param string $tableName The name of the table in which a document should be patched
+     * @return string The query to patch a document by its ID
+     * @throws DocumentException If the database mode has not been set
+     */
+    public static function byId(string $tableName): string
+    {
+        return self::update($tableName, Query::whereById());
+    }
+
+    /**
+     * Query to patch (partially update) a document via a comparison on a JSON field
+     *
+     * @param string $tableName The name of the table in which documents should be patched
+     * @param array|Field[] $field The field comparison to match
+     * @param string $conjunction How to handle multiple conditions (optional; defaults to `AND`)
+     * @return string The query to patch documents via field comparison
+     * @throws DocumentException If the database mode has not been set
+     */
+    public static function byFields(string $tableName, array $field, string $conjunction = 'AND'): string
+    {
+        return self::update($tableName, Query::whereByFields($field, $conjunction));
+    }
+}