mysql workbench建表時PK,NN,UQ,BIN,UN,ZF,AI，workbenchuq

mysql workbench建表時PK,NN,UQ,BIN,UN,ZF,AI，workbenchuq
[intrinsic column flags] (基本欄位類型標識)
- PK: primary key (column is part of a pk) 主鍵- NN: not null (column is nullable) 非空- UQ: unique (column is part of a unique key) 唯一- AI: auto increment (the column is auto incremented when rows are inserted) 自增
[additional data type flags, depend on used data type] 擴充資料類型標記
- BIN: binary (if dt is a blob or similar, this indicates that is binary data, rather than text) 二進位(比text更大的位元據)- UN: unsigned (for integer types, see docs: “10.2. Numeric Types”) 整數- ZF: zero fill (rather a display related flag, see docs: “10.2. Numeric Types”)值中最有意義的位元組總為0，並且不儲存。  ps: ZF個人理解指的是帶有小數預留位置的資料相當於金額類型的資料。