Initial SQLite development (#1)

Reviewed-on: #1

src/Query.php

@@ -0,0 +1,77 @@
+<?php declare(strict_types=1);
+
+namespace BitBadger\PDODocument;
+
+/**
+ * Query construction functions
+ */
+class Query
+{
+    /**
+     * Create a SELECT clause to retrieve the document data from the given table
+     *
+     * @param string $tableName The name of the table from which document data should be retrieved
+     * @return string The SELECT clause to retrieve a document from the given table
+     */
+    public static function selectFromTable(string $tableName): string
+    {
+        return "SELECT data FROM $tableName";
+    }
+
+    /**
+     * Create a WHERE clause fragment to implement a comparison on fields in a JSON document
+     *
+     * @param Field[] $fields The field comparison to generate
+     * @param string $conjunction How to join multiple conditions (optional; defaults to AND)
+     * @return string The WHERE clause fragment matching the given fields and parameter
+     */
+    public static function whereByFields(array $fields, string $conjunction = 'AND'): string
+    {
+        return implode(" $conjunction ", array_map(fn($it) => $it->toWhere(), $fields));
+    }
+
+    /**
+     * Create a WHERE clause fragment to implement an ID-based query
+     *
+     * @param string $paramName The parameter name where the value of the ID will be provided (optional; default @id)
+     * @return string The WHERE clause fragment to match by ID
+     */
+    public static function whereById(string $paramName = ':id'): string
+    {
+        return self::whereByFields([Field::EQ(Configuration::$idField, 0, $paramName)]);
+    }
+
+    /**
+     * Query to insert a document
+     *
+     * @param string $tableName The name of the table into which a document should be inserted
+     * @return string The INSERT statement for the given table
+     */
+    public static function insert(string $tableName): string
+    {
+        return "INSERT INTO $tableName VALUES (:data)";
+    }
+
+    /**
+     * Query to save a document, inserting it if it does not exist and updating it if it does (AKA "upsert")
+     *
+     * @param string $tableName The name of the table into which a document should be saved
+     * @return string The INSERT...ON CONFLICT query for the document
+     */
+    public static function save(string $tableName): string
+    {
+        return self::insert($tableName)
+            . " ON CONFLICT ((data->>'" . Configuration::$idField . "')) DO UPDATE SET data = EXCLUDED.data";
+    }
+
+    /**
+     * Query to update a document
+     *
+     * @param string $tableName The name of the table in which the document should be updated
+     * @return string The UPDATE query for the document
+     */
+    public static function update(string $tableName): string
+    {
+        return "UPDATE $tableName SET data = :data WHERE " . self::whereById();
+    }
+}