问题
In MySQL Workbench table editor there are 7 column flags available: PK, NN, UQ, BIN, UN, ZF, AI.
PK obviously stands for Primary Key. What about others?
回答1:
PK - Primary Key
NN - Not Null
BIN - Binary (stores data as binary strings. There is no character set so sorting and comparison is based on the numeric values of the bytes in the values.)
UN - Unsigned (non-negative numbers only. so if the range is -500 to 500, instead its 0 - 1000, the range is the same but it starts at 0)
UQ - Create/remove Unique Key
ZF - Zero-Filled (if the length is 5 like INT(5) then every field is filled with 0’s to the 5th digit. 12 = 00012, 400 = 00400, etc. )
AI - Auto Increment
G - Generated column. i.e. value generated by a formula based on the other columns
回答2:
Here is the source of these column flags
http://dev.mysql.com/doc/workbench/en/wb-table-editor-columns-tab.html
回答3:
This exact question is answered on mySql workbench-faq:
Hover over an acronym to view a description, and see the Section 8.1.11.2, “The Columns Tab” and MySQL CREATE TABLE documentation for additional details.
That means hover over an acronym in the mySql Workbench table editor.
Section 8.1.11.2, “The Columns Tab”
来源：https://stackoverflow.com/questions/3663952/what-do-column-flags-mean-in-mysql-workbench