列出mysql

Question

我想用PHP列出MySQL数据库表中的列数。我怎样才能做到这一点？

Answer 1

The INFORMATION_SCHEMA built into every MySQL server可用于查找此信息。

尝试此查询以获取当前数据库中每个表的列表及其列数。

SELECT TABLE_NAME, COUNT(*) AS column_count
  FROM INFORMATION_SCHEMA.COLUMNS
 WHERE TABLE_SCHEMA=DATABASE()
 GROUP BY TABLE_NAME

如果您只想要一个表的结果，请尝试这样的事情。

SELECT COUNT(*) AS column_count
  FROM INFORMATION_SCHEMA.COLUMNS
 WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='mytable'

Answer 2

如果您想计算列数，请使用

SELECT COUNT(*)
   FROM INFORMATION_SCHEMA.COLUMNS
   WHERE table_schema = 'database_name'
         AND table_name = 'tbl_name';