Removed unused legacy functions and split the functions into their own file and use function.php to call them

functions/db.php

@@ -0,0 +1,224 @@
+<?php
+
+// Prepared-statement DB wrapper layer.
+// NOTE: NEW DB LAYER - adoption pending. Not yet called from app code;
+// intended target for the gradual prepared-statement migration. Do not remove.
+// Split from the former monolithic functions.php
+
+
+/**
+ * Simple mysqli helper functions
+ * - Prepared statements under the hood
+ * - "Old style" INSERT/UPDATE SET feeling
+ */
+
+/**
+ * Core executor: prepares, binds, executes.
+ *
+ * @throws Exception on error
+ */
+function dbExecute(mysqli $mysqli, string $sql, array $params = []): mysqli_stmt
+{
+    $stmt = $mysqli->prepare($sql);
+    if (!$stmt) {
+        throw new Exception('MySQLi prepare error: ' . $mysqli->error . ' | SQL: ' . $sql);
+    }
+
+    if (!empty($params)) {
+        $types  = '';
+        $values = [];
+
+        foreach ($params as $param) {
+            if (is_int($param)) {
+                $types .= 'i';
+            } elseif (is_float($param)) {
+                $types .= 'd';
+            } elseif (is_bool($param)) {
+                $types .= 'i';
+                $param  = $param ? 1 : 0;
+            } elseif (is_null($param)) {
+                $types .= 's';
+                $param  = null;
+            } else {
+                $types .= 's';
+            }
+            $values[] = $param;
+        }
+
+        if (!$stmt->bind_param($types, ...$values)) {
+            throw new Exception('MySQLi bind_param error: ' . $stmt->error . ' | SQL: ' . $sql);
+        }
+    }
+
+    if (!$stmt->execute()) {
+        throw new Exception('MySQLi execute error: ' . $stmt->error . ' | SQL: ' . $sql);
+    }
+
+    return $stmt;
+}
+
+/**
+ * Fetch all rows as associative arrays.
+ */
+function dbFetchAll(mysqli $mysqli, string $sql, array $params = []): array
+{
+    $stmt   = dbExecute($mysqli, $sql, $params);
+    $result = $stmt->get_result();
+    if ($result === false) {
+        return [];
+    }
+    return $result->fetch_all(MYSQLI_ASSOC);
+}
+
+/**
+ * Fetch a single row (assoc) or null if none.
+ */
+function dbFetchOne(mysqli $mysqli, string $sql, array $params = []): ?array
+{
+    $stmt   = dbExecute($mysqli, $sql, $params);
+    $result = $stmt->get_result();
+    if ($result === false) {
+        return null;
+    }
+    $row = $result->fetch_assoc();
+    return $row !== null ? $row : null;
+}
+
+/**
+ * Fetch a single scalar value (first column of first row) or null.
+ */
+function dbFetchValue(mysqli $mysqli, string $sql, array $params = [])
+{
+    $row = dbFetchOne($mysqli, $sql, $params);
+    if ($row === null) {
+        return null;
+    }
+    return reset($row);
+}
+
+/**
+ * INSERT using "SET" style.
+ * Example:
+ *   $id = dbInsert($mysqli, 'clients', [
+ *       'client_name' => $name,
+ *       'client_type' => $type,
+ *   ]);
+ *
+ * @return int insert_id
+ *
+ * @throws InvalidArgumentException
+ * @throws Exception
+ */
+function dbInsert(mysqli $mysqli, string $table, array $data): int
+{
+    if (empty($data)) {
+        throw new InvalidArgumentException('dbInsert called with empty $data');
+    }
+
+    $setParts = [];
+    foreach ($data as $column => $_) {
+        $setParts[] = "$column = ?";
+    }
+
+    $sql    = "INSERT INTO $table SET " . implode(', ', $setParts);
+    $params = array_values($data);
+
+    dbExecute($mysqli, $sql, $params);
+
+    return $mysqli->insert_id;
+}
+
+function dbUpdate(
+    mysqli $mysqli,
+    string $table,
+    array $data,
+    $where,
+    array $whereParams = []
+): int {
+    if (empty($data)) {
+        throw new InvalidArgumentException('dbUpdate called with empty $data');
+    }
+    if (empty($where)) {
+        throw new InvalidArgumentException('dbUpdate requires a WHERE clause');
+    }
+
+    $setParts = [];
+    foreach ($data as $column => $_) {
+        $setParts[] = "$column = ?";
+    }
+
+    if (is_array($where)) {
+        $whereParts  = [];
+        $whereParams = [];
+        foreach ($where as $column => $value) {
+            $whereParts[]  = "$column = ?";
+            $whereParams[] = $value;
+        }
+        $whereSql = implode(' AND ', $whereParts);
+    } else {
+        $whereSql = $where;
+    }
+
+    $sql    = "UPDATE $table SET " . implode(', ', $setParts) . " WHERE $whereSql";
+    $params = array_merge(array_values($data), $whereParams);
+
+    $stmt = dbExecute($mysqli, $sql, $params);
+    return $stmt->affected_rows;
+}
+
+/**
+ * DELETE helper.
+ *
+ * WHERE can be:
+ *   - array: ['client_id' => $id] (auto "client_id = ?")
+ *   - string: 'client_id = ?' (use with $whereParams)
+ *
+ * @return int affected_rows
+ *
+ * @throws InvalidArgumentException
+ * @throws Exception
+ */
+function dbDelete(
+    mysqli $mysqli,
+    string $table,
+    $where,
+    array $whereParams = []
+): int {
+    if (empty($where)) {
+        throw new InvalidArgumentException('dbDelete requires a WHERE clause');
+    }
+
+    if (is_array($where)) {
+        $whereParts  = [];
+        $whereParams = [];
+        foreach ($where as $column => $value) {
+            $whereParts[]  = "$column = ?";
+            $whereParams[] = $value;
+        }
+        $whereSql = implode(' AND ', $whereParts);
+    } else {
+        $whereSql = $where;
+    }
+
+    $sql  = "DELETE FROM $table WHERE $whereSql";
+    $stmt = dbExecute($mysqli, $sql, $whereParams);
+    return $stmt->affected_rows;
+}
+
+/**
+ * Transaction helpers (optional sugar).
+ */
+function dbBegin(mysqli $mysqli): void
+{
+    $mysqli->begin_transaction();
+}
+
+function dbCommit(mysqli $mysqli): void
+{
+    $mysqli->commit();
+}
+
+function dbRollback(mysqli $mysqli): void
+{
+    $mysqli->rollback();
+}