1:创建索引:索引可以提高查询速度,但影响插入数据的速度,但前者带来的好处要远远高于后者:)
CREATE TABLE Products(pid INTEGER AUTO_INCRMENT PRIMARY KEY,user_name VARCHAR(50) NOT NULL,full_name VARCHAR(100),user_email VARCHAR(150) NOT NULL,birthdate DATE,INDEX (user_name));
//新增
CREATE INDEX index_name ON tableName (columns);
2:外键
CREATE TABLE forums(form_id INTEGER AU...