你能帮我解决这些sql问题吗？

Question

你好，我正在使用 phpmyadmin 3.3.9 。我有一个 sql 问题，我根本不知道问题是什么..

代码如下：

CREATE TABLE metars(
metar varchar( 255 ) NOT NULL default '',
timestamp timestamp( 14 ) NOT NULL ,
station varchar( 4 ) NOT NULL,
PRIMARY KEY ( station ) ,
UNIQUE KEY station( station )
) ENGINE = MYISAM 

错误如下：

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '( 14 ) NOT NULL , station varchar( 4 ) NOT NULL default '', PRIMARY KE' at line 3

Answer 1

尝试使用 timestamp timestamp NOT NULL ，
时间戳没有长度/格式选项（即：不适用于 mysql 5.1，请参阅 ypercube 的评论）

请参阅 http://dev.mysql.com/doc/refman/5.1/en/create-table.html

data_type:
    BIT[(length)]
  | TINYINT[(length)] [UNSIGNED] [ZEROFILL]
  | SMALLINT[(length)] [UNSIGNED] [ZEROFILL]
  | MEDIUMINT[(length)] [UNSIGNED] [ZEROFILL]
  | INT[(length)] [UNSIGNED] [ZEROFILL]
  | INTEGER[(length)] [UNSIGNED] [ZEROFILL]
  | BIGINT[(length)] [UNSIGNED] [ZEROFILL]
  | REAL[(length,decimals)] [UNSIGNED] [ZEROFILL]
  | DOUBLE[(length,decimals)] [UNSIGNED] [ZEROFILL]
  | FLOAT[(length,decimals)] [UNSIGNED] [ZEROFILL]
  | DECIMAL[(length[,decimals])] [UNSIGNED] [ZEROFILL]
  | NUMERIC[(length[,decimals])] [UNSIGNED] [ZEROFILL]
  | DATE
  | TIME
  | TIMESTAMP
  | DATETIME
  | YEAR
  | CHAR[(length)]
 [...]

但我会避免使用关键字和/或类型名称作为标识符。

Answer 2

“timestamp”是 MySQL 的关键字。因此，将列名“timestamp”更改为其他名称或用grave(`) 括起来。并且不必设置时间戳类型的列长度。

而PRIMARY KEY也意味着唯一性。所以，UNIQUE KEY 站（station）在这里是没有必要的。

CREATE TABLE metars(
metar varchar( 255 ) NOT NULL default '',
`timestamp` timestamp,
station varchar( 4 ) NOT NULL,
PRIMARY KEY ( station )
) ENGINE = MYISAM 

Answer 3

CREATE TABLE metars(
`metar` varchar( 255 ) NOT NULL default '',
`timestamp` timestamp( 14 ) NOT NULL ,
`station` varchar( 4 ) NOT NULL,
PRIMARY KEY ( `station` ) ,
UNIQUE KEY station( `station` )
) ENGINE = MYISAM

这个应该不错