hadoop大數(shù)據(jù)二期11.28課程內(nèi)容-課件0302hive深入使用一

課程大綱4Hive

表的創(chuàng)建1235Hive

數(shù)據(jù)類型Hive

數(shù)據(jù)遷移Hive

常見查詢HiveUDF編程課程大綱4Hive

表的創(chuàng)建1235Hive

數(shù)據(jù)類型Hive

數(shù)據(jù)遷移Hive

常見查詢HiveUDF編程DataBaseCreate/Drop/Alter

DatabaseCreate/Drop/Alter

DatabaseShow

DatabaseDescribe

DatabaseTableCreate/Drop/Truncate

TableManualDDL-Create/Drop/TruncateTableCreate/Drop/Truncate

TableCreate/Drop/Truncate

TableCreate

Tablecreate

table

emp(empno

int,

ename

string,job

string,mgr

int,hiredate

string,sal

double,comm

double,deptno

int)row

format

delimited

fields

terminated

by

'\t';員工表：create

table

dept(deptno

int,

dname

string,loc

string)row

format

delimited

fields

terminated

by

'\t';部門表：Load

DataLOAD

DATA

[LOCAL]

INPATH

'filepath'[OVERWRITE]

INTO

TABLE

tablename

[PARTITION(partcol1=val1,

partcol2=val2

...)]LOCAL：從本地文件加載數(shù)據(jù)到hive表；否則從HDFS加載數(shù)據(jù)到hive表；OVERWRITE：是否覆蓋表中已有數(shù)據(jù)；load

data

local

inpath

'/home/hadoop/data/emp.txt'

overwrite

into

table

emp;load

data

local

inpath

'/home/hadoop/data/dept.txt'

overwrite

into

table

dept;Create

Table

As

Select

()Create

Table

LikeCreate/Drop/Truncate

TableCreate/Drop/Truncate

TableExternal

Tables表也稱之為MANAGED_TABLE；默認

在/user/hive/warehouse下，也可以通過location指定；刪除表時，會刪除表數(shù)據(jù)以及元數(shù)據(jù)；外部表稱之為EXTERNAL_TABLE；在創(chuàng)建表時可以自己指定

位置(LOCATION)；刪除表時，只會刪除元數(shù)據(jù)不會刪除表數(shù)據(jù)；External

TablesPartitioned

Tables分區(qū)表實際上就是對應(yīng)一個HDFS文件系統(tǒng)上的獨立的文件夾，該文件夾下是該分區(qū)所有的數(shù)據(jù)文件。Hive中的分區(qū)就是分，把一個大的數(shù)據(jù)集根據(jù)業(yè)務(wù)需要分割更小成的數(shù)據(jù)集。在查詢時通過WHERE子句中的表達式來選擇查詢所需要的指定的分區(qū)，這樣的查詢效率會提高很多。create

table

dept_partition(deptno

int,dname

string,loc

string)PARTITIONED

BY

(event_month

string)ROW

FORMAT

DELIMITED

FIELDS

TERMINATED

BY

'\t';Partitioned

TablesPartitioned

TablesPartitioned

TablesPartitioned

Tables作業(yè)十三、Hive表的創(chuàng)建與使用作業(yè)十三、Hive表的創(chuàng)建與使用課程大綱4Hive

表的創(chuàng)建1235Hive

數(shù)據(jù)類型Hive

數(shù)據(jù)遷移Hive

常見查詢HiveUDF編程Hive

Data

TypesHive

Data

TypesPrimitive

Types課程大綱4Hive

表的創(chuàng)建1235Hive

數(shù)據(jù)類型Hive

數(shù)據(jù)遷移Hive

常見查詢HiveUDF編程Hive

Data

ManipulationLoading

files

into

tablesLOAD

DATA

[LOCAL]

INPATH

'filepath'[OVERWRITE]

INTO

TABLE

tablename[PARTITION

(partcol1=val1,

partcol2=val2

...)]Loading

files

into

tablesLoading

files

into

tablesLoading

files

into

tablesHive

Data

ManipulationHive

Data

Manipulation課程大綱4Hive

表的創(chuàng)建1235Hive

數(shù)據(jù)類型Hive

數(shù)據(jù)遷移Hive

常見查詢HiveUDF編程QueriesQueriesSELECT[ALL

|

DISTINCT]

select_expr,

select_expr,

...FROM

table_reference[WHERE

where_condition]