CREATE DB_DISCOVERY RULE

描述

CREATE DB_DISCOVERY RULE 语法用于创建数据库发现规则

语法定义

语法 铁路图

CreateDatabaseDiscoveryRule ::=
  'CREATE' 'DB_DISCOVERY' 'RULE' ifNotExists? databaseDiscoveryDefinition (',' databaseDiscoveryDefinition)*
ifNotExists ::=
  'IF' 'NOT' 'EXISTS'
databaseDiscoveryDefinition ::=
  ruleName '(' 'STORAGE_UNITS' '(' storageUnitName (',' storageUnitName)* ')' ',' 'TYPE' '(' 'NAME' '=' typeName (',' propertiesDefinition)? ')' ',' 'HEARTBEAT' '(' propertiesDefinition ')' ')' 
propertiesDefinition ::=
  'PROPERTIES' '(' key '=' value (',' key '=' value)* ')'
ruleName ::=
  identifier
storageUnitName ::=
  identifier
typeName ::=
  identifier
discoveryHeartbeatName ::=
  identifier
key ::=
  string
value ::=
  literal

补充说明

• discoveryType 指定数据库发现服务类型，ShardingSphere 内置支持 MySQL.MGR；
• 重复的 ruleName 将无法被创建；
• ifNotExists 子句用于避免出现 Duplicate db_discovery rule 错误。

示例

• 创建数据库发现规则

CREATE DB_DISCOVERY RULE db_discovery_group_0 (
    STORAGE_UNITS(ds_0, ds_1, ds_2),
    TYPE(NAME='MySQL.MGR',PROPERTIES('group-name'='92504d5b-6dec')),
    HEARTBEAT(PROPERTIES('keep-alive-cron'='0/5 * * * * ?'))
);

• 使用 ifNotExists 子句创建数据库发现规则

CREATE DB_DISCOVERY RULE IF NOT EXISTS db_discovery_group_0 (
    STORAGE_UNITS(ds_0, ds_1, ds_2),
    TYPE(NAME='MySQL.MGR',PROPERTIES('group-name'='92504d5b-6dec')),
    HEARTBEAT(PROPERTIES('keep-alive-cron'='0/5 * * * * ?'))
);

保留字

CREATE、DB_DISCOVERY、RULE、STORAGE_UNITS、TYPE、NAME、PROPERTIES、HEARTBEAT

相关链接

• 保留字