HiveQL DML 常用QL示例资料

 hive 2.1.1  DML操作

将文件加载到hive表

//官方指导
LOAD DATA [LOCAL] INPATH 'filepath' [OVERWRITE] INTO TABLE tablename [PARTITION (partcol1=val1, partcol2=val2 ...)]

//示例
LOAD DATA LOCAL INPATH '/root/a.txt' OVERWRITE INTO TABLE testdb.test partition(dd='a',ed='2018');

说明：local 如果没有指定local关键字，则filepath引用表所在的文件系统中的文件。

查询数据到hive表

//官方指导
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;

//示例
insert into table test2  partition(area,year) select id,ad,bd,cd,dd,ed  from test where ed='2019';

说明：后面的字段对应的是分区字段

　　into是拼接新的值

　　overwrite是新值覆盖掉全部旧的值，又分区会覆盖指定分区内的值

表中写入到文件系统

//官方指导
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)

//示例
insert  overwrite local directory  '/root' row format delimited fields terminated by '	 ' collection items terminated by ',' map keys terminated by ':' lines terminated by '
'  select * from test;

说明：如果不指定字段分割方式 将以  ^ A   ^ B  ^C 分割

修改表数据

//官方指导
更新只支持在ACID表上执行。 
客户端
hive.support.concurrency – true
hive.enforce.bucketing – true (Not required as of Hive 2.0) 
hive.exec.dynamic.partition.mode – nonstrict
hive.txn.manager – org.apache.hadoop.hive.ql.lockmgr.DbTxnManager
服务端
hive.compactor.initiator.on – true (See table below for more details)
hive.compactor.worker.threads – a positive number on at least one instance of the Thrift metastore service

Standard Syntax:
UPDATE tablename SET column = value [, column = value ...] [WHERE expression]

//示例
//服务端
set hive.compactor.initiator.on = true ;
set hive.compactor.worker.threads = 1;
//客户端
set hive.support.concurrency = true;
set hive.enforce.bucketing = true;
set hive.exec.dynamic.partition.mode = nonstrict;
set hive.txn.manager = org.apache.hadoop.hive.ql.lockmgr.DbTxnManager;
update testdb.test set ad = 'xiaoming' where id =1 ;

说明:创建的表要为分桶表，还要设置参数为 'transactional'='true'

　　不支持子查询

　　当where条件匹配上了才能更新

　　分区，分桶的列不能更新

　　设置hive.optimize.sort.dynamic.partition=false可以提高效率

　　属性都可以在hive-site.xml文件中配置 

删除表数据

//官方指导
只支持在ACID表上执行。 
客户端
hive.support.concurrency – true
hive.enforce.bucketing – true (Not required as of Hive 2.0) 
hive.exec.dynamic.partition.mode – nonstrict
hive.txn.manager – org.apache.hadoop.hive.ql.lockmgr.DbTxnManager
服务端
hive.compactor.initiator.on – true (See table below for more details)
hive.compactor.worker.threads – a positive number on at least one instance of the Thrift metastore service

Standard Syntax:
DELETE FROM tablename [WHERE expression]

//示例
//服务端
set hive.compactor.initiator.on = true ;
set hive.compactor.worker.threads = 1;
set hive.optimize.sort.dynamic.partition = false;
//客户端
set hive.support.concurrency = true;
set hive.enforce.bucketing = true;
set hive.exec.dynamic.partition.mode = nonstrict;
set hive.txn.manager = org.apache.hadoop.hive.ql.lockmgr.DbTxnManager;

delete from testdb.test where id = 1;

说明:见修改表数据说明

从hive2.2开始支持表合并