百度试题 题目以下能删除一列的语句是() A.alter table tb_student remove ageB.alter table tb_student drop column ageC.alter table tb_student delete column ageD.alter table tb_student delete age相关知识点: 试题来源: 解析 B 反馈 收藏
百度试题 题目以下能删除一列的语句是()A.alter table tb_student remove ageB.alter table tb_student drop column ageC.alter table tb_student delete column ageD.alter table tb_student delete age 相关知识点: 试题来源: 解析 B 反馈 收藏
MySQL中create table语句的基本语法是: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,…)] [table_options] [select_statement] TEMPORARY:该关键字表示用MySQL create table新建的表为临时表,此表在当前会话结束后将自动消失。临时表主要被应用于存储过程中,对于目前尚不支持存储过程的...
你不能使用子查询从某张表中查询出一个值,然后再将这个值插入这张表中..mysql不能这样用..so..使用视图、临时表或者用两个语句吧..
alter table语句在表tb_student上建立主键索引,--修改表名[renameto]altertabletab_namerenametotab_new;--修改字段类型(修改字段相对位置)[modify]altertabletab_namemodifyfieldtype(first/beforefield1);--修改字段默认值/是否为空/自动增长altertabletab_namemodi
设使用如下SQL语句创建了学生表tb_student: CREATE TABLE tb_student( sno CHAR(10) NOT NULL PRIMARY KEY, sname CHAR(20) NOT NULL, CHAR(2), age INT) ENGINE=InnoDB; 下列选项中,能够插入到该表中的记录是A.(’A18010’,’李丽’,NULL,NULL)B.(A18010,’李丽’,女,19)C.
CREATE TABLE IF NOT EXISTS table1 ( col_1 STRING, col_2 INT ) STORED AS orc LOCATION 'obs://bucketName/filePath'; Example 2: Creating an OBS Partitioned Table Example description: Create a partitioned table named student, which is partitioned using facultyNo and classNo. In practice,...
使用如下语句成功定义了数据表tb_student:CREATE TABLE tb_student(Sno CHAR(8) PRIMARY KEY,Sname VARCHAR(20) NOT NULL UNIQUE, CHAR(2),Sage TINYINT,Monitor CHAR(8),CONSTRAINT FK_S2 Foreign key (Monitor) REFERENCES tb_student(Sno)) ;若要在tb_student表中输入如下记录,必须符合相应的约束。...
1.MySQL对CREATE TABLE IF NOT EXISTS SELECT的处理 MySQL支持创建持数据表时判断是否存在,存在则不创建,不存在则创建,相应语句如下: --格式 CREATE...TABLE IF NOT EXISTS [Table Definition]; --示例 CREATE TABLE IF NOT EXISTS student(id int unsigned not...null primary key,name varchar(32) not null...
修改数据表 tb_student 的存储引擎为 InnoDB ,可以使用下面的( )语句。A.ALTER TABLE tb_ student DEFAULT CHARSET= InnoDB.ALTER TABLE tb_ student C.ALTER TABLE tb_student ENGINE=InnoDD.Alter TABLE tb_ student AD AUTO_NCREMENT= nnoD B ; ALTER TABLE tb_student ENNE=nnoDB ;Alter TABLE tb_ st...