题目描述存在如下的视图:create view emp_v as select * from employees where emp_no >10005;CREATE TABLE employees (emp_no int(11) NOT NULL,birth_date date NOT NULL,first_name varchar(14) NOT NULL,last_name varchar(16) NOT NULL,gender char(1) NOT NULL,hire_date date NOT NULL,PRIMARY KEY (emp_no))...
将所有to_date为9999-01-01的全部更新为NULL,且 from_date更新为2001-01-01。CREATE TABLE IF NOT EXISTS titles_test (id int(11) not null primary key,emp_no int(11) NOT NULL,title varchar(50) NOT NULL,from_date date NOT NULL,to_date date DEFAULT NULL);
题目描述分页查询employees表,每5行一页,返回第2页的数据CREATE TABLE employees (emp_no int(11) NOT NULL,birth_date date NOT NULL,first_name varchar(14) NOT NULL,last_name varchar(16) NOT NULL,gender char(1) NOT NULL,hire_date date NOT NULL,PRIMARY KEY (emp_no));
题目描述删除emp_no重复的记录,只保留最小的id对应的记录。CREATE TABLE IF NOT EXISTS titles_test (id int(11) not null primary key,emp_no int(11) NOT NULL,title varchar(50) NOT NULL,from_date date NOT NULL,to_date date DEFAULT NULL);
查找排除当前最大、最小salary之后的员工的平均工资avg_salary。CREATE TABLE salaries ( emp_no int(11) NOT NULL,salary int(11) NOT NULL,from_date date NOT NULL,to_date date NOT NULL,PRIMARY KEY (emp_no,from_date));输出格式:avg_salary69462.5555555556
针对库中的所有表生成select count(*)对应的SQL语句CREATE TABLE employees (emp_no int(11) NOT NULL,birth_date date NOT NULL,first_name varchar(14) NOT NULL,last_name varchar(16) NOT NULL,gender char(1) NOT NULL,hire_date date NOT NULL,PRIMARY KEY (emp_no));create table emp_bonus(emp_no int not null,...
题目描述存在actor表,包含如下列信息:CREATE TABLE IF NOT EXISTS actor (actor_id smallint(5) NOT NULL PRIMARY KEY,first_name varchar(45) NOT NULL,last_name varchar(45) NOT NULL,last_update timestamp NOT NULL DEFAULT (datetime('now','localtime')));现在在last_update后面新增加一列名字为create_date, ...