CREATE SHADOW RULE

Description

The CREATE SHADOW RULE syntax is used to create a shadow rule.

Syntax

Grammar Railroad diagram

  1. CreateShadowRule ::=
  2.   'CREATE' 'SHADOW' 'RULE' ifNotExists? shadowRuleDefinition (',' shadowRuleDefinition)*
  4. ifNotExists ::=
  5.   'IF' 'NOT' 'EXISTS'
  7. shadowRuleDefinition ::=
  8.   ruleName '(' storageUnitMapping shadowTableRule (',' shadowTableRule)* ')'
  10. storageUnitMapping ::=
  11.   'SOURCE' '=' storageUnitName ',' 'SHADOW' '=' storageUnitName
  13. shadowTableRule ::=
  14.   tableName '(' shadowAlgorithm ')'
  16. shadowAlgorithm ::=
  17.   'TYPE' '(' 'NAME' '=' shadowAlgorithmType ',' propertiesDefinition ')'
  19. ruleName ::=
  20.   identifier
  22. storageUnitName ::=
  23.   identifier
  25. tableName ::=
  26.   identifier
  28. algorithmName ::=
  29.   identifier
  31. shadowAlgorithmType ::=
  32.   string
  34. propertiesDefinition ::=
  35.   'PROPERTIES' '(' key '=' value (',' key '=' value)* ')'
  37. key ::=
  38.   string
  40. value ::=
  41.   literal

Supplement

  • Duplicate ruleName cannot be created;
  • storageUnitMapping specifies the mapping relationship between the source database and the shadow library. You need to use the storage unit managed by RDL, please refer to STORAGE UNIT;
  • shadowAlgorithm can act on multiple shadowTableRule at the same time;
  • If algorithmName is not specified, it will be automatically generated according to ruleName, tableName and shadowAlgorithmType;
  • shadowAlgorithmType currently supports VALUE_MATCH, REGEX_MATCH and SQL_HINT;
  • ifNotExists caluse is used for avoid Duplicate shadow rule error.

Example

  • Create a shadow rule
  1. CREATE SHADOW RULE shadow_rule(
  2.   SOURCE=demo_ds,
  3.   SHADOW=demo_ds_shadow,
  4.   t_order(TYPE(NAME="SQL_HINT")), 
  5.   t_order_item(TYPE(NAME="VALUE_MATCH", PROPERTIES("operation"="insert","column"="user_id", "value"='1')))
  6. );
  • Create a shadow rule with ifNotExists clause
  1. CREATE SHADOW RULE IF NOT EXISTS shadow_rule(
  2.   SOURCE=demo_ds,
  3.   SHADOW=demo_ds_shadow,
  4.   t_order(TYPE(NAME="SQL_HINT")), 
  5.   t_order_item(TYPE(NAME="VALUE_MATCH", PROPERTIES("operation"="insert","column"="user_id", "value"='1')))
  6. );

Reserved word

CREATE, SHADOW, RULE, SOURCE, SHADOW, TYPE, NAME, PROPERTIES