创建表 - 云数据库 ClickHouse

本文介绍如何使用DMS（Data Management Service）在云数据库ClickHouse中创建表。

前提条件

已完成快速入门的如下步骤。

操作步骤

1.在数据管理DMS控制台的SQL Console页面中，输入CREATE TABLE语句创建本地表。

语法：

CREATE TABLE [IF NOT EXISTS] [db.]local_table_name ON CLUSTER cluster
(
    name1 [type1] [DEFAULT|MATERIALIZED|ALIAS expr1],
    name2 [type2] [DEFAULT|MATERIALIZED|ALIAS expr2],
    ...
    INDEX index_name1 expr1 TYPE type1(...) GRANULARITY value1,
    INDEX index_name2 expr2 TYPE type2(...) GRANULARITY value2
) ENGINE = engine_name()
[PARTITION BY expr]
[ORDER BY expr]
[PRIMARY KEY expr]
[SAMPLE BY expr]
[SETTINGS name=value, ...];

参数说明：

参数	说明
`db`	指定数据库的名称，默认为当前选择的数据库。
`local_table_name`	本地表名。
`cluster`	指定集群的名称，固定为default。
`name1,name2`	列名。
`type1,type2`	列类型。
`engine_name`	表引擎类型，具体请参见表引擎。说明单副本版为MergeTree，双副本版为ReplicatedMergeTree。
`PARTITION BY`	指定分区键。
`ORDER BY`	指定排序键。
`PRIMARY KEY`	指定主键。
`SAMPLE BY`	抽样表达式。如果要使用抽样表达式，主键中必须包含这个表达式。
`SETTINGS`	影响性能的其他参数。

说明

更多参数说明，请参见Create Table。

示例：

CREATE TABLE clickhouse_demo.ontime_local ON CLUSTER default
(
    `Year`                            UInt16,
    `Quarter`                         UInt8,
    `Month`                           UInt8,
    `DayofMonth`                      UInt8,
    `DayOfWeek`                       UInt8,
    `FlightDate`                      Date,
    `Reporting_Airline`               String,
    `DOT_ID_Reporting_Airline`        Int32,
    `IATA_CODE_Reporting_Airline`     String,
    `Tail_Number`                     String,
    `Flight_Number_Reporting_Airline` String,
    `OriginAirportID`                 Int32,
    `OriginAirportSeqID`              Int32,
    `OriginCityMarketID`              Int32,
    `Origin`                          FixedString(5),
    `OriginCityName`                  String,
    `OriginState`                     FixedString(2),
    `OriginStateFips`                 String,
    `OriginStateName`                 String,
    `OriginWac`                       Int32,
    `DestAirportID`                   Int32,
    `DestAirportSeqID`                Int32,
    `DestCityMarketID`                Int32,
    `Dest`                            FixedString(5),
    `DestCityName`                    String,
    `DestState`                       FixedString(2),
    `DestStateFips`                   String,
    `DestStateName`                   String,
    `DestWac`                         Int32,
    `CRSDepTime`                      Int32,
    `DepTime`                         Int32,
    `DepDelay`                        Int32,
    `DepDelayMinutes`                 Int32,
    `DepDel15`                        Int32,
    `DepartureDelayGroups`            String,
    `DepTimeBlk`                      String,
    `TaxiOut`                         Int32,
    `WheelsOff`                       Int32,
    `WheelsOn`                        Int32,
    `TaxiIn`                          Int32,
    `CRSArrTime`                      Int32,
    `ArrTime`                         Int32,
    `ArrDelay`                        Int32,
    `ArrDelayMinutes`                 Int32,
    `ArrDel15`                        Int32,
    `ArrivalDelayGroups`              Int32,
    `ArrTimeBlk`                      String,
    `Cancelled`                       UInt8,
    `CancellationCode`                FixedString(1),
    `Diverted`                        UInt8,
    `CRSElapsedTime`                  Int32,
    `ActualElapsedTime`               Int32,
    `AirTime`                         Nullable(Int32),
    `Flights`                         Int32,
    `Distance`                        Int32,
    `DistanceGroup`                   UInt8,
    `CarrierDelay`                    Int32,
    `WeatherDelay`                    Int32,
    `NASDelay`                        Int32,
    `SecurityDelay`                   Int32,
    `LateAircraftDelay`               Int32,
    `FirstDepTime`                    String,
    `TotalAddGTime`                   String,
    `LongestAddGTime`                 String,
    `DivAirportLandings`              String,
    `DivReachedDest`                  String,
    `DivActualElapsedTime`            String,
    `DivArrDelay`                     String,
    `DivDistance`                     String,
    `Div1Airport`                     String,
    `Div1AirportID`                   Int32,
    `Div1AirportSeqID`                Int32,
    `Div1WheelsOn`                    String,
    `Div1TotalGTime`                  String,
    `Div1LongestGTime`                String,
    `Div1WheelsOff`                   String,
    `Div1TailNum`                     String,
    `Div2Airport`                     String,
    `Div2AirportID`                   Int32,
    `Div2AirportSeqID`                Int32,
    `Div2WheelsOn`                    String,
    `Div2TotalGTime`                  String,
    `Div2LongestGTime`                String,
    `Div2WheelsOff`                   String,
    `Div2TailNum`                     String,
    `Div3Airport`                     String,
    `Div3AirportID`                   Int32,
    `Div3AirportSeqID`                Int32,
    `Div3WheelsOn`                    String,
    `Div3TotalGTime`                  String,
    `Div3LongestGTime`                String,
    `Div3WheelsOff`                   String,
    `Div3TailNum`                     String,
    `Div4Airport`                     String,
    `Div4AirportID`                   Int32,
    `Div4AirportSeqID`                Int32,
    `Div4WheelsOn`                    String,
    `Div4TotalGTime`                  String,
    `Div4LongestGTime`                String,
    `Div4WheelsOff`                   String,
    `Div4TailNum`                     String,
    `Div5Airport`                     String,
    `Div5AirportID`                   Int32,
    `Div5AirportSeqID`                Int32,
    `Div5WheelsOn`                    String,
    `Div5TotalGTime`                  String,
    `Div5LongestGTime`                String,
    `Div5WheelsOff`                   String,
    `Div5TailNum`                     String
)ENGINE = ReplicatedMergeTree()
 PARTITION BY toYYYYMM(FlightDate)
 PRIMARY KEY (intHash32(FlightDate))
 ORDER BY (intHash32(FlightDate))
 SAMPLE BY intHash32(FlightDate)
SETTINGS index_granularity= 8192 ;

2.创建分布式表，方便数据的写入和查询。

语法：

CREATE TABLE  [db.]d_table_name ON CLUSTER cluster
 AS db.local_table_name ENGINE = Distributed(cluster, db, local_table_name [, sharding_key])

参数说明：

参数	说明
`db`	指定数据库的名称，默认为当前选择的数据库。
`d_table_name`	分布式表名。
`cluster`	指定集群的名称，固定为default。
`local_table_name`	已创建的本地表名。
`sharding_key`	分片表达式。

说明

更多参数说明，请参见Create Table。

示例：

CREATE TABLE ontime_local_distributed ON CLUSTER default
 AS clickhouse_demo.ontime_local  
ENGINE = Distributed(default, clickhouse_demo, ontime_local, rand());

下一步

导入数据