如何在Laravel PHP中內部聯接表

Question

我有這個查詢

SELECT * FROM books b 
INNER JOIN categories c ON b.category_id = c.id 
WHERE c.category_name = 'Comics'

因此通過參數傳遞

SELECT * FROM books b 
INNER JOIN categories c ON b.category_id = c.id 
WHERE c.category_name = ?

我這樣在拉拉維（Laravel）試過

writer::join('categories','categories.id','=','writers.category_id')
  ->where('categories.category_name','Comics')
  ->get();

並帶有參數

writer::join('categories','categories.id','=','writers.category_id')
  ->where(['categories.category_name' => $cat])
  ->get();

我沒有在Laravel中獲得任何數據！ 我有什么錯誤嗎？

Answer 1

嘗試以下方法：

writer::join('categories','categories.id','=','writers.category_id')
->where([
  ['categories.category_name', '=', $cat]
])->get();

要么

writer::join('categories','categories.id','=','writers.category_id')
->where('categories.category_name', $cat)
->get();