计数SQL查询PHP

Question

我想为其中的每个图库计数，这是我的查询：

$req = db_query("SELECT count(*) FROM node,node_file WHERE node.nid = node_file.nid AND nid = ".$value['nid']);

这是两个表：
node_file：

nid  |fid   |
-------------
  1  |  1   | 
-------------
  1  |  2   |  
-------------
  1  |  3   |
-------------
  2  |  1   |
-------------
  2  |  2   |
-------------
  2  |  3   |

节点：

 nid |type  |
-------------
  1  |Gallery1| 
-------------
  2  |gallery2|  

错误： Query : SELECT count(*) FROM node,node_file WHERE node.nid = node_file.nid AND nid = 34 Message : SQLSTATE[23000]: Integrity constraint violation: 1052 Column 'nid' in where clause is ambiguous

谢谢！

Answer 1

您的两个表都具有列nid并且您正在使用AND子句中的列，因此您需要指定它属于哪个表。

SELECT 
    count(*)
FROM
    node,
    node_file
WHERE
    node.nid = node_file.nid AND node.nid = 34

要么

SELECT 
    count(*)
FROM
    node,
    node_file
WHERE
    node.nid = node_file.nid AND node_file.nid = 34

Answer 2

用这个

$req = db_query("SELECT count(*) FROM node,node_file WHERE node.nid = node_file.nid AND node.nid = ".$value['nid']);