hive DML

/*
	从查询语句中获取数据插入某张表
	语法：
		Standard syntax:
		INSERT OVERWRITE TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...) 			[IF NOT EXISTS]] select_statement1 FROM from_statement;
		INSERT INTO TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...)] 				select_statement1 FROM from_statement;
 
		Hive extension (multiple inserts):
		FROM from_statement
		INSERT OVERWRITE TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...) 			[IF NOT EXISTS]] select_statement1
		[INSERT OVERWRITE TABLE tablename2 [PARTITION ... [IF NOT EXISTS]] 							select_statement2]
		[INSERT INTO TABLE tablename2 [PARTITION ...] select_statement2] ...;
			FROM from_statement
		INSERT INTO TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...)] 				select_statement1
		[INSERT INTO TABLE tablename2 [PARTITION ...] select_statement2]
		[INSERT OVERWRITE TABLE tablename2 [PARTITION ... [IF NOT EXISTS]] 							select_statement2] ...;
 
		Hive extension (dynamic partition inserts):
			INSERT OVERWRITE TABLE tablename PARTITION (partcol1[=val1], partcol2[=val2] 				...) select_statement FROM from_statement;
			INSERT INTO TABLE tablename PARTITION (partcol1[=val1], partcol2[=val2] ...) 				select_statement FROM from_statement;
*/
--注意：这种方式插入数据的时候需要预先创建好结果表
--从表中查询数据插入结果表
	INSERT OVERWRITE TABLE psn9 SELECT id,name FROM psn
--从表中获取部分列插入到新表中
	from psn
	insert overwrite table psn9
	select id,name 
	insert into table psn10
	select id
3、Writing data into the filesystem from queries
/*
	将查询到的结果插入到文件系统中
	语法：	
	Standard syntax:
		INSERT OVERWRITE [LOCAL] DIRECTORY directory1
  		[ROW FORMAT row_format] [STORED AS file_format] (Note: Only available starting 			with Hive 0.11.0)
  		SELECT ... FROM ...
 
	Hive extension (multiple inserts):
		FROM from_statement
		INSERT OVERWRITE [LOCAL] DIRECTORY directory1 select_statement1
		[INSERT OVERWRITE [LOCAL] DIRECTORY directory2 select_statement2] ... 
		row_format
  		: DELIMITED [FIELDS TERMINATED BY char [ESCAPED BY char]] [COLLECTION ITEMS 			TERMINATED BY char]
        [MAP KEYS TERMINATED BY char] [LINES TERMINATED BY char]
        [NULL DEFINED AS char] (Note: Only available starting with Hive 0.13)
*/
--注意：路径千万不要填写根目录，会把所有的数据文件都覆盖
--将查询到的结果导入到hdfs文件系统中
	insert overwrite directory '/result' select * from psn;
--将查询的结果导入到本地文件系统中
	insert overwrite local directory '/result' select * from psn;