ALTERTABLEname RENAMETOnew_nameALTERTABLEnameADDCOLUMNS (col_spec[, col_spec ...])ALTERTABLEnameDROP[COLUMN]column_name --- 译注:这个drop命令,我在工作中,并没有生效,而是利用表级别的REPLACE进行替换式删除字段的ALTERTABLEname CHANGE column_name new_name new_typeALTERTABLEnameREPLACECOLUMNS (col_spec...
修改后源数据库模式如下图所示。
This chapter explains how to create a table and how to insert data into it. The conventions of creating a table in HIVE is quite similar to creating a table using SQL. Create Table Statement Create Table is a statement used to create a table in Hive. The syntax and example are as follo...
ALTER TABLE test_changeCHANGEa a1 INT;将 a 列的名字改为 a1. ALTER TABLE test_changeCHANGEa a1 STRING AFTER b;将 a 列的名字改为 a1,a 列的数据类型改为 string,并将它放置在列 b 之后。新的表结构为: b int, a1 string,cint. ALTER TABLE test_changeCHANGEb b1 INT FIRST;会将 b 列的名...
Alter Table是非常常见的一种DDL操作,在Hive中,使用Alter Table可以修改表名,修改表属性,添加字段,修改字段数据类型等等。需要注意的是,ALTER TABLE修改的只是MySQL中的相关元数据,不会对表数据产生影响,用户需要手动确保实际数据符合元数据的定义,否则查询不会返回预期的结果。但在分区数比较多的情况下,修改表名这类...
name, new_name, column_name, new_column_name, and table_name_* are user-defined parameters.The following statement is used to rename a table.ALTER TABLEnameRENAME TOnew_n
CREATE TABLE 使用 Hive 格式 CREATE TABLE CONSTRAINT CREATE TABLE USING CREATE TABLE LIKE CREATE VIEW CREATE VOLUME DECLARE VARIABLE DROP CATALOG DROP CONNECTION DROP CREDENTIAL DROP DATABASE DROP FUNCTION 投遞地點 DROP PROVIDER DROP RECIPIENT DROP SCHEMA DROP SHARE DROP TABLE DROP VARIABLE DROP...
在mysql运维操作中会经常使用到alter这个修改表的命令，alter tables允许修改一个现有表的结构，比如增加或...
ALTERTABLEusersRENAMECOLUMNidTOuser_id; Rename columnidtouser_idin theuserstable if tableusersand columnidexists: ALTERTABLEIFEXISTSusersRENAMEcolumnIFEXISTSidtouser_id; Change type of columnidtobigintin theuserstable: ALTERTABLEusersALTERCOLUMNidSETDATATYPEbigint; ...
Sets restrictions on data that is added to a specific table. This parameter is enforced during INSERT operations, but is not enforced during a LOAD HADOOP operation, or on data that is made available outside of the database manager (by using Hive operations, for example). search-condition Th...