Class SqlMappingRule

java.lang.Object
org.sqlproc.engine.impl.SqlMappingRule

public class SqlMappingRule extends Object
The precompiled mapping entity for one external META SQL mapping rule. Instances of this class are created by the ANTLR parser. The grammar itself is defined in SqlMapping.g. The main runtime contracts is merge(SqlMappingRule, SqlProcessResult).

Schematically:

 SqlMappingRule = SqlMappingItem+
     SqlMappingItem = dbName$sqlType$javaName^(value(=value2)?)*.javaName...
 
Author:
Vladimir Hudec
  • Field Details

    • logger

      protected static org.slf4j.Logger logger
      The internal slf4j logger.
    • raw

      String raw
      A raw representation this output value mapping
    • mappings

      private Map<String,SqlMappingItem> mappings
      All sub-elements based on ANTLR grammar defined in SqlMapping.g. Every sub-element is one mapping item.
  • Constructor Details

    • SqlMappingRule

      public SqlMappingRule()
      Creates a new instance. It's used from inside ANTLR parser.
    • SqlMappingRule

      public SqlMappingRule(String raw)
      Creates a new instance. It's used from inside ANTLR parser.
  • Method Details

    • getInstance

      public static SqlMappingRule getInstance(String name, String mappingStatement, SqlTypeFactory typeFactory) throws SqlEngineException
      Simple factory method (design pattern). The new instance of precompiled mapping rule is created from the String input by the ANTLR parser.
      Parameters:
      name - the name of this mapping rule
      mappingStatement - String representation of mapping rule
      typeFactory - the factory for the META types construction
      Returns:
      the new instance of precompiled mapping rule
      Throws:
      SqlEngineException - in the case of ANTRL parsing exception
    • getRaw

      public String getRaw()
      Returns raw representation this output value mapping
      Returns:
      raw representation this output value mapping
    • addMapping

      void addMapping(SqlMappingItem item)
      Adds a new Mapping item, which is a mapping rule for one column.
      Parameters:
      item - the mapping item
    • getMappings

      Map<String,SqlMappingItem> getMappings()
      Returns a collection of all mapping items in this mapping rule.
      Returns:
      the collection of all mapping items
    • merge

      public static SqlMappingResult merge(SqlMappingRule mapping, SqlProcessResult processResult)
      Merge mapping rule for one META SQL query based on SqlMapping.g and SqlStatement.g. The mapping rule based on SqlMapping.g has the higher priority compared to mapping rule based on SqlStatement.g. The mapping rule based on SqlStatement.g obtains a list of real output values.
      Parameters:
      mapping - the mapping rule based on SqlMapping.g
      processResult - contains a mapping rule based on SqlStatement.g
      Returns:
      the crate for output mapping rule and database row identities