Created table with generated columns throw an error

Daniele Sartori :

I am trying to build my table in MySQL following this answer. Hower i keep getting errors in MySQL even launching the same query used as example in the answer

this query is from documentation and works correctly

CREATE TABLE triangle (
  sidea DOUBLE,
  sideb DOUBLE,
  sidec DOUBLE AS (SQRT(sidea * sidea + sideb * sideb)) stored
);

this query comes from the answer i've linked and it gives me an error

CREATE TABLE IF NOT EXISTS MyTable (
  id int NOT NULL AUTO_INCREMENT,
  name varchar(50) NOT NULL,
  description varchar(50) NOT NULL,
  slug text NOT NULL AS (SHA2(CONCAT(name, description), 256) STORED,
  PRIMARY KEY (id)
) DEFAULT CHARSET=utf8;

this is the query i am trying to execute based on the answer which is giving me also an error

CREATE TABLE IF NOT EXISTS myTable(
  id BIGINT NOT NULL AUTO_INCREMENT,  
  first VARCHAR(104) NOT NULL DEFAULT '',  
  second DATETIME NULL,
  third DATETIME NULL,
  fourth VARCHAR(255) NULL,
  table_key varchar(64) NOT NULL AS (SHA2(concat_ws(',',first, second, third, fourth), 256)) stored unique,
  PRIMARY KEY (id),
  INDEX (first));

can you help me figuring out why it's not working?

Note that SHA2(concat_ws(',',first, second, third, fourth), 256) this works in a normal select statement

EDIT

this is the error i am getting

Query execution failed

Reason:

Errore SQL [1064] [42000]: (conn:28) You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'AS (SHA2(CONCAT(name, description), 256) STORED,

  PRIMARY KEY (id)

) DEFAULT ' at line 5
Query is : CREATE TABLE IF NOT EXISTS MyTable (

  id int NOT NULL AUTO_INCREMENT,

  name varchar(50) NOT NULL,

  description varchar(50) NOT NULL,

  slug text NOT NULL AS (SHA2(CONCAT(name, description), 256) STORED,

  PRIMARY KEY (id)

) DEFAULT CHARSET=utf8

Sebastian Brosch :

You have to add the NOT NULL after the AS part (computed column definition) of the column like this:

CREATE TABLE IF NOT EXISTS myTable(
  id BIGINT NOT NULL AUTO_INCREMENT,  
  first VARCHAR(104) NOT NULL DEFAULT '',  
  second DATETIME NULL,
  third DATETIME NULL,
  fourth VARCHAR(255) NULL,
  table_key varchar(64) AS (SHA2(concat_ws(',',first, second, third, fourth), 256)) stored unique NOT NULL,
  PRIMARY KEY (id),
  INDEX (first)
);

Also have a look at the official document of CREATE TABLE. There you can find the description of the datatype syntax. The definition of the computed column is part of the datatype.

Created table with generated columns throw an error

Guess you like