drop table if exists `dept_emp` ; drop table if exists `salaries` ; CREATE TABLE `dept_emp` ( `emp_no` int(11) NOT NULL, `dept_no` char(4) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`dept_no`)); CREATE ... 您的查询意图是要...
create [standard | raw] table [if not exists] <table_name> (colname1 data_type1, colname2 data_type2, ...); 重命名表 rename table <old_table_name> to <new_table_name>; 删除表 drop table [if exists] <table_name>; 演示 create table t_user1(f_userid int, f_username varchar(...
DROP TABLE IF EXISTS `departments`; #看到这里发现了建表语句,也就是没有建库语句,因此若想把sql语句导入指定库,需要先创建库 /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `departments` ( `dept_no` char(4) NOT NU...
DROP { DBSPACE <dbspace-name> | { DATATYPE [ IF EXISTS ] | DOMAIN } <datatype-name> | EVENT [ IF EXISTS ] <event-name> | INDEX [ IF EXISTS ] [ [ <owner>].<table-name>.]<index-name> | MESSAGE <message-number> | TABLE [ IF EXISTS ] [ <owner>.]<table-name> | VIEW [...
drop 删除:删除表格:drop table if exists t_student;如果这张表存在,删除 四、创建表格 在数据库:bjpowernode 中创建表格:t_student 1、选中你要操作的数据库:use bjpowernode; 2、开始在该数据库中创建你需要的表格: create table t_student( no int, ...
DROPDATABASEIFEXISTSmytest1;2. 对比 TRUNCATE TABLE 和 DELETE FROM 相同点：都可以实现对表中所有...
hive>ALTERTABLEemployeeADDCOLUMNS(dept STRING COMMENT'Department name'); -- 有一些文章里说 add columns dept STRING COMMENT 'comment' ;但是在一些高版本里,需要把你需要加的列放到括号里() JDBC Program The JDBC program to add a column to a table is given below. ...
SQL> drop table dept cascade constraints; Table dropped. How to drop multiple tables in oracle There might be a requirement to drop multiple tables in a single step begin execute immediate 'drop table t_name_1'; execute immediate 'drop table t_name_2'; ...
DROP TABLE IF EXISTS myHadoopTable Drop the view VDEPT. DROP VIEW VDEPT The authorization ID HEDGES attempts to drop an alias. DROP ALIAS A1The alias HEDGES.A1 is removed from the catalogs. Hedges attempts to drop an alias, but specifies T1 as the alias-name, where T1 is the name ...
nameRESTRICTTABLEtable-name2TABLE HIERARCHYroot-table-name,tablespace-nameTRANSFORMALLgroup-nameFORtype-nameTHRESHOLDthreshold-nameTRIGGERtrigger-nameTRUSTED CONTEXTcontext-nameTYPEtype-nameRESTRICTTYPE MAPPINGtype-mapping-nameUSAGE LISTusage-list-nameUSER MAPPING FORauthorization-nameUSERSERVERserver-nameVARIABLE...