embed

The EGL embed keyword allows you to include the fields of one structured record in a second structured record without creating a substructure. An SQL record that is an I/O object for relational database access must have such a flat structure.

The only reason to use the embed keyword in place of a structure field name is to avoid adding a level of hierarchy. A structure field identified by the embed keyword has these restrictions:
  • Can point to the format of a Record part, but not to a DataItem part
  • Cannot specify an array or include a primitive-type specification

Syntax


Syntax diagram for the embed statement
level
A level number within the structured record.
recordType
The name from a record definition. The fields from this definition will be included at the current position and specified level.

Examples

In the following example, the keyword embed includes all the fields from the address record into record1: 
  Record address type basicRecord
    10 streetAddress1 CHAR(30);
    10 streetAddress2 CHAR(30);
    10 city CHAR(20);
  end

  Record record1 type serialRecord
  {
    fileName = "myFile"
  }
    10 person CHAR(30);
    10 embed address;
  end
The internal structure of the Record part is now flat:
  Record record1 type serialRecord
  {
    fileName = "myFile"
  }
    10 person CHAR(30);
    10 streetAddress1 CHAR(30);
    10 streetAddress2 CHAR(30);
    10 city CHAR(20);
  end
You can also use the embed keyword to declare identical structures in two records. The keyword does not overwrite the properties of those records with the properties from the embedded record: 
  Record common type serialRecord
  {
    fileName = "mySerialFile"
  }
    10 a BIN(10);
    10 b CHAR(10);
  end

  Record recordA type indexedRecord
  {
    fileName = "myFile",
    keyItem = "a"
  }
    embed common; // accepts the structure of common, 
                  // not the properties
  end

  Record recordB type relativeRecord
  {
    fileName = "myOtherFile",
    keyItem = "a"
  }
    embed common;
  end
The last two Record parts are equivalent to these declarations:
  Record recordA type indexedRecord
  {
    fileName = "myFile",
    keyItem = "a"
  }
    10 a BIN(10);
    10 b CHAR(10);
  end

  Record recordB type relativeRecord
  {
    fileName = "myOtherFile",
    keyItem = "a"
  }
    10 a BIN(10);
    10 b CHAR(10);
  end