1、創建數據庫語句

create table persons('id' INT NOT NULL AUTO_INCREMENT,'lastname' VARCHAR(255) NOT NULL,'firstname' VARCHAR(255) NOT NULL,PRIMARY KEY ('ID'))
DEFAULT CHARACTER SET = latin1
COLLATE = latin1_swedish_ci;

2、創建數據庫時，PK、NN、UQ、BIN、UN、AF、AI的含義

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 value. 12 = 00012, 400 = 00400, etc. )

AI - Auto Increment

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轉載于:https://www.cnblogs.com/sunflower627/p/4619014.html

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