mySQL表创建失败 - 错误1064

Question

I am using the mysql admin GUI tool to create a table. Here is the query language that results in an error:

CREATE TABLE `environment`.`moisture` (
  `city_id` INT,
  `date_holding` VARCHAR,
  `time_holding` VARCHAR,
  `open` REAL,
  `high` REAL,
  `low` REAL,
  `close` REAL,
)
CHARACTER SET utf8;

My date and time are not of the format mysql likes so I selected VARCHAR as the type for those columns and referred to them as holding columns until I can run queries to make the necessary conversions.

When I try to execute this via the GUI I get the following:

Error executing SQL commands to create table.
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 'NOT NULL,
`time_holding` VARCHAR NOT NULL,
`open` REAL NOT NULL,
`high` RE' at line 3 (error 1064)

Any idea why I am getting this? I have checked to see if I am using any reserved words but that does not seem to be the case.

Your help would be greatly appreciated.

Answer 1

The first error you have is due to that VARCHAR fields need a length like this: VARCHAR(30) .

The second error (you'll get if you fix the 2 varchars) is the comma before the last parenthesis.

CREATE TABLE `environment`.`moisture` (
  `city_id` INT,
  `date_holding` VARCHAR(30),  --or whatever length you want
  `time_holding` VARCHAR(20),  --same
  `open` REAL,
  `high` REAL,
  `low` REAL,
  `close` REAL  --- no comma here
)
CHARACTER SET utf8;

---

Side note: You do know that MySQL has specific types to handle dates and times, don't you? So you could have:

CREATE TABLE `environment`.`moisture` (
  `city_id` INT,
  `date_holding` date,
  `time_holding` time,
  ...