删除PRIMARYKEY约束条件及其所有依赖约束条件的语法是什么() A: AALTER TABLE table_name DROP CONSTRAINT constraint_name CASCADE B: BALTER TABLE table_name DROP CONSTRAINT FOREIGN KEY CASCADE C: CDROP CONSTRAINT table_name(constraint_name) D: DALTER TABLE table_name DROP CONSTRAINT constraint_name
删除PRIMARYKEY约束条件及其所有依赖约束条件的语法是什么() A: AALTER TABLE table_name DROP CONSTRAINT constraint_name CASCADE B: BALTER TABLE table_name DROP CONSTRAINT FOREIGN KEY CASCADE C: CDROP CONSTRAINT table_name(constraint_name) D: DALTER TABLE table_name DROP CONSTRAINT constraint_name
如下不能正确执行的语句是( ) A: select * from table_name where 1>2 B: truncate table table_name C: delete from table_name where null=null D: alter table table_name add column idd int
如下不能正确执行的语句是( ) A: select * from table_name where 1>2 B: truncate table table_name C: delete from table_name where null=null D: alter table table_name add column idd int
要删掉表中的某字段,可以使用的SQL命令是( )。 A: ALTER<br/>TABLE table_name DROP COLUMN field_name B: ALTER<br/>TABLE table_name ALTER COLUMN field_name C: DELETE<br/>FROM TABLE D: DROP<br/>TABLE E: UPDATE<br/>table_name set column_name = value
要删掉表中的某字段,可以使用的SQL命令是( )。 A: ALTER<br/>TABLE table_name DROP COLUMN field_name B: ALTER<br/>TABLE table_name ALTER COLUMN field_name C: DELETE<br/>FROM TABLE D: DROP<br/>TABLE E: UPDATE<br/>table_name set column_name = value
创建表的关键字是() A: create table B: create table_name C: create database D: create view
创建表的关键字是() A: create table B: create table_name C: create database D: create view
若要在基本表S中增加一列NAME,应使用下列的哪一行SQL语句()。 A: ADD TABLE S (NAME CHAR(8)) B: ADD TABLE S ALTER (NAME CHAR(8)) C: ALTER TABLE S ADD (NAME CHAR(8)) D: ALTER TABLE S (ADNAME CHAR(8))
若要在基本表S中增加一列NAME,应使用下列的哪一行SQL语句()。 A: ADD TABLE S (NAME CHAR(8)) B: ADD TABLE S ALTER (NAME CHAR(8)) C: ALTER TABLE S ADD (NAME CHAR(8)) D: ALTER TABLE S (ADNAME CHAR(8))
关于查询中列的别名, 以下()语句是不正确的(选一项) A: Select name as '姓名' from table B: Select name as姓名 from table where id =1 C: Sleect name = 姓名 from table D: Select names姓名 from table
关于查询中列的别名, 以下()语句是不正确的(选一项) A: Select name as '姓名' from table B: Select name as姓名 from table where id =1 C: Sleect name = 姓名 from table D: Select names姓名 from table
下面哪条语句可以查询姓“张”并且年龄等于20岁的用户,请问用哪条语句? A: Select * From table Where name like "%张%" And intAge=20 B: Select * From table Where name like "张%" And intAge=20 C: Select * From table Where name like "张%" And intAge="20" D: Select * From table Where name="张" And intAge=20
下面哪条语句可以查询姓“张”并且年龄等于20岁的用户,请问用哪条语句? A: Select * From table Where name like "%张%" And intAge=20 B: Select * From table Where name like "张%" And intAge=20 C: Select * From table Where name like "张%" And intAge="20" D: Select * From table Where name="张" And intAge=20
下来定义表的约束语法,错误的是() A: create table t1(id number primary key,name varchar2(10)) B: create table t1(id number constraint p_k primary key(id),name varchar2(10)) C: create table t1(id number constraint p_k primary key,name varchar2(10)) D: create table t1(id number,name varchar2(10),primary key(id))
下来定义表的约束语法,错误的是() A: create table t1(id number primary key,name varchar2(10)) B: create table t1(id number constraint p_k primary key(id),name varchar2(10)) C: create table t1(id number constraint p_k primary key,name varchar2(10)) D: create table t1(id number,name varchar2(10),primary key(id))
hive创建表并指定列分隔符的正确的HQL是( )。 A: create table dbtest(id int, name string) row format delimited terminate by ','; B: create table dbtest(int id, string name) row format delimited by ','; C: create table dbtest(id int, name string) row format delimited fields terminated by ','; D: create table dbtest(int id, string name) row format delimited columns fields terminated by ',';
hive创建表并指定列分隔符的正确的HQL是( )。 A: create table dbtest(id int, name string) row format delimited terminate by ','; B: create table dbtest(int id, string name) row format delimited by ','; C: create table dbtest(id int, name string) row format delimited fields terminated by ','; D: create table dbtest(int id, string name) row format delimited columns fields terminated by ',';
If there is already a table with the same name existed in the database, to overwrite the original table by query, the query type that should be used is (). A: Delete B: Append C: Generate table D: Update
If there is already a table with the same name existed in the database, to overwrite the original table by query, the query type that should be used is (). A: Delete B: Append C: Generate table D: Update