DROP DATABASE IF EXISTS test; # 如果存在test,则删除该数据库 SHOW DATABASES ; #查看数据库 USE test; #选择数据库 1. 2. 3. 二、创建表 1. 创建基本表语法: CREATE TABLE [IF [NOT] EXIST ] 表名( 字段1 数据类型 [<列级完整性约束1> <列级完整性约束2> …], 字段2 数据类型 [<列级完整...
CREATE TABLE CREATE TABLE 更新时间:2025-01-06 14:40:43 分享 描述 该语句用来在数据库中创建一张新表。 语法 CREATE TABLE [IF NOT EXISTS] table_name (table_definition_list) [table_option_list] [partition_option] [AS] select; CREATE TABLE [IF NOT EXISTS] table_name LIKE table_name; table...
ALTER TABLE table_name DROP column_name; 3、删除表 1)DROP:将表结构和表数据都删除,释放表空间 DROP TABLE IF EXISTS table_name; 2)TRUNCATE:清空表中的数据,表结构保留 TRUNCATE TABLE table_name; 3)DELETE:删除后可以ROLLBACK DELETE FROM table_name; 4、重命名表:用ALTER TABLE+RENAME(rename) 方式...
(field-commalist) REFERENCES table [(reffield-commalist)] [ON DELETE ref-action] [ON UPDATE ref-action] [NOCHECK] }] [ SHARD [ KEY (field-commalist) [ COSHARD [ WITH ] [(]table[)] ] ] ] [WITH table-option ::= { %CLASSPARAMETER paramname [=] value } , } [ STORAGETYPE [...
4 DROP TABLE IF EXISTS `files`; 5 CREATE TABLE `files` ( 6 `id` int(11) NOT NULL, 7 `fileName` varchar(50) DEFAULT NULL, 8 `filePath` varchar(200) DEFAULT NULL, 9 `updateDate` datetime DEFAULT NULL, 10 `userId` int(11) DEFAULT NULL, ...
The following query deletes all the columns from theemployeetable and replaces it withempandnamecolumns: hive>ALTERTABLEemployeeREPLACECOLUMNS ( eidINTempidInt, ename STRING name String); JDBC Program Given below is the JDBC program to replaceeidcolumn withempidandenamecolumn withname. ...
_table_name [ ( ref_column [ ,... n ] ) ] [ ON DELETE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ NOT FOR REPLICATION ] | CHECK [ NOT FOR REPLICATION ] ( logical_expression ) } <table_index> ...
1 CREATE DATABASE 句法 2 3 CREATE DATABASE [IF NOT EXISTS] db_name 4 5 CREATE DATABASE 以给定名字创建一个数据库。允许的数据库名规则在章节 6.1.2 数据库、表、索引、列和别名 中被给出。 如果数据库已经存在,并且你...
CREATE [ { GLOBAL | LOCAL } TEMPORARY ] TABLE [ IF NOT EXISTS ] [ <owner>. ]<table-name> … ( column-definition [ column-constraint ] … [ , column-definition [ column-constraint ] …] [ , table-constraint ] … ) |{ ENABLE | DISABLE } RLV STORE …[ IN <dbspace-name> ] …...
CREATE TABLEIF NOT EXISTStable-nameElement-listOFtype-name1typed-table-optionsLIKEtable-name1view-namenicknamecopy-optionsas-result-tablecopy-optionsmaterialized-query-definitionstaging-table-definition●ORGANIZE BYROWCOLUMNROW USING1Dimensions-clauseKEY SEQUENCEsequence-key-specINSERT TIME●DATA CAPTURENONECHA...