Error on record: The alias [arrayField[1].field] cannot be used because it contains illegal characters

May i know the context? whether you are trying to use smart service or any other functions?

that array field in the CDT is a nested CDT. I already came up with a workaround:

replaced this

rf!arrayField[1].field

with this

 index(index(rf!arrayField,1,null),"field",null)

but still wonder why I am getting the error using the first syntax

The CDT which you are trying to fetch is empty which has no structure defined in data

for example: if output empty cdt is like this

field1:

field2:

field3:

then Dot notation will work

If output cdt is empty {} without any structure, then Dot notation fails. Index function has default value functionality within it to handle this situation and so it works in index function and not in Dot notation

The CDT which you are trying to fetch is empty which has no structure defined in data

for example: if output empty cdt is like this

field1:

field2:

field3:

then Dot notation will work

If output cdt is empty {} without any structure, then Dot notation fails. Index function has default value functionality within it to handle this situation and so it works in index function and not in Dot notation

it is a really good argument but the CDT is not empty, I am able to see the field value in the nested cdt if I pass it as parameter to an interface by using the index function

Can you post the sample CDT structure please..

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:tns="urn:com:appian:types" targetNamespace="urn:com:appian:types">
  <xsd:complexType name="CDT_NAME">
    <xsd:annotation>
      <xsd:appinfo source="appian.jpa">@Table(name="TABLE_NAME")</xsd:appinfo>
      <xsd:documentation><![CDATA[TABLE_NAME]]></xsd:documentation>
    </xsd:annotation>
    <xsd:sequence>
      <xsd:element name="txt_prop" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_PROP", columnDefinition="VARCHAR2(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_nom" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_NOM", columnDefinition="VARCHAR2(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_regio" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_REGIO", columnDefinition="VARCHAR2(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_zona" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_ZONA", columnDefinition="VARCHAR2(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_nom_ejec" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_NOM_EJEC", columnDefinition="VARCHAR2(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_nom_anlst" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_NOM_ANLST", columnDefinition="VARCHAR2(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_anio" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_ANIO", columnDefinition="VARCHAR2(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_buc" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_BUC", columnDefinition="CHAR(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="txt_gpo" nillable="true" type="xsd:string">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="TXT_GPO", columnDefinition="CHAR(200)")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="id_prop" nillable="true" type="xsd:int">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Column(name="ID_PROP", columnDefinition="NUMBER") @JoinColumn(name="ID_PROP")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="id_prop_det" nillable="true" type="xsd:int">
        <xsd:annotation>
          <xsd:appinfo source="appian.jpa">@Id @Column(name="ID_PROP_DET", nullable=false, columnDefinition="NUMBER") @SequenceGenerator(name="SQ_TABLE_NAME", sequenceName="SQ_TABLE_NAME") @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="SQ_TABLE_NAME")</xsd:appinfo>
        </xsd:annotation>
      </xsd:element>
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>

Best to not use dot notation ever, and use index or property functions.  Also, sometimes array[1] will return the character at index 1 if array is a string.  This gets confusing if your array is actually returning only 1 element which can be interpreted as a string. 

I shy away from [] always and use index or property.