MySQL 8 does not yet support the BOOLEAN type as specified in the SQL standard. There is a DDL "type" called BOOL, which is just an alias for TINYINT: create table t(b bool); select table_name, column_name, data_type, column_type from information_schema.columns where table_name = 't'; The above produces: TABLE_NAME|COLUMN_NAME|DATA_TYPE|COLUMN_TYPE| ----------|-----------|---------|-----------| t |b |tinyint |tinyint(1) | Notice … Continue reading How to Map MySQL’s TINYINT(1) to Boolean in jOOQ →

I would like to make a quick MySQL 101 about numeric types in MySQL and especially explain the difference between the numeric type attributes and the maximum value that a numeric type can store.

Someone asked me yesterday why when he inserts a value in a table, the value 127 appears instead of the value 160 that he’s just inserted.
Ok, let me explain, consider this table :

What happens if you want to insert this row in the table :

sql > insert into product values (160, 554, "iPad mini");
Query OK, 1 row affected, 1 warning (0.01 sec)
sql > show warnings;
+---------+------+---------------------------------------------+
| Level   | Code | Message                                     |
+---------+------+---------------------------------------------+
| Warning | 1264 | Out of range value for column 'id' at row 1 | …

Are bools bools in MySQL - no they're not! Lets show this:

mysql> CREATE TABLE healthcheck ( isworking bool ) ENGINE=MEMORY;Query OK, 0 rows affected (0.14 sec)

mysql> show create table healthcheck\G

*************************** 1. row ***************************

Table: healthcheck

Create Table: CREATE TABLE `healthcheck` (

`isworking` tinyint(1) DEFAULT NULL

) ENGINE=MEMORY DEFAULT CHARSET=latin1

1 row in set (0.00 sec)

So a 'bool' in MySQL is actually a signed tinyint that has range -128 to 127. This information is actually hidden away in the bowels of the MySQL documentation at:http://dev.mysql.com/doc/refman/5.0/en/numeric-type-overview.html"[bool] These types are synonyms for TINYINT(1). A value …

(At least in Drizzle)

Brian merged my jay-and-stewart-remove-pack_flag branch and it’s now in trunk. Removing pack_flag was a task for the bell milestone and in true collaborative effort, it took more than one person to unravel its dark mysteries. Hats go off to Jay who bravely ripped more of it out with the aid of excellent Seattle coffee. I finished it off with removing the last remnants and fixing an outstanding bug (and at the same time making us look at the DECIMAL code and shuddering in fear of what it may mean).

With pack_flag gone, we can now do insane things like remove the last bits of TINYINT from the code, as previous to removing pack_flag, if you did that, things …