Before importing graph data, familiarize yourself with the graph data formats supported by GES.

• GES supports the loading of raw graph data in the standard CSV format. If your raw data is not in the specified format, convert it to the format supported by GES.
• GES graph data consists of the vertex, edge, and metadata files.
  • Vertex files store vertex data.
  • Edge files store edge data.
  • Metadata is used to describe the formats of data in vertex and edge files.

Concept Description

Graph data is imported based on the property graph model in GES, so you must learn the concept of the property graph.

A property graph is a directed graph consisting of vertices, edges, labels, and properties.

• A vertex is also called a node, and an edge is also called a relationship. Nodes and relationships are the most important entities.
• The metadata is used to describe vertex and edge properties. The metadata consists of multiple labels and each label consists of one or more properties.
• Vertices with the same label belong to a group or a set.
• Each vertex or edge can have only one label.

In the following example, the graph data consists of three vertices and three edges. Vivian, Eric, and Lethal Weapon indicate vertices. (Vivian, Eric), (Vivian, Lethal Weapon), and (Eric, Lethal Weapon) indicate edges. user and movie indicate the vertex types (labels), and rate and friends indicate the relationship types (labels).

Figure 1 Graph data format example

• Label

  A label is a collection of properties. It describes all property data formats contained within a vertex or an edge.

  

  If the same Property Name is defined in different labels, the Cardinality and Data Type in different labels must be the same.

• Property

  A property refers to the data format of a single property and contains three fields.

  • Property Name: Indicates the name of a property. It contains 1 to 256 characters and cannot contain special characters such as angle brackets (<>) and ampersands (&).
    

    A label cannot contain two properties with the same name.

  • cardinality: Indicates the composite type of data. Possible values are single, list, and set.
    • single indicates that the data of this property has a single value, such as a digit or a character string.
      

      If the value of a single property in a data file is value1;value2, value1;value2 is regarded as a single value.

    • list and set indicate that data of this property consists of multiple values separated by semicolons (;).
      • list: The values are placed in sequence and can be repeated. For example, 1;1;1 contains three values.
      • set: The values are in random sequence and must be unique. Duplicate values will be overwritten. For example, 1;1;1 contains only one value (1).
      

      list and set do not support the char array data type.

  • Data Type: Indicates the data type. The following table lists the data types supported by GES.

    Table 1 Supported data types

    Type	Description
    char	Character
    char array	Fixed-length character string (The maximum length must be specified.) NOTE: Only single supports the data type. If the data is a character string, you are advised to set this parameter to char array. If it is set to string, the import is slower.
    float	Float type (32-bit float)
    double	Double float type (64-bit float)
    bool	bool type. Possible values are (0/1) and (true/false).
    long	Long integer (value range: -2^63 to 2^63-1)
    int	Integer (value range: -2^31 to 2^31-1)
    date	Date. Currently, the following formats are supported: YYYY-MM-DD HH:MM:SS YYYY-MM-DD NOTE: The value of MM or DD must consist of two digits. If the day or month number contains only one digit, add 0 before it, for example, 05/01.
    enum	Enumeration (you need to specify the number of enumeration types and each enumeration value). For details, see Figure 2.
    string	Variable character string NOTE: The string length is not fixed, which affects data import efficiency. You are advised to use char array instead. You can define the length of char array based on service requirements. It is recommended that the length be less than or equal to 32 characters.

The following figure shows the metadata example:

Figure 2 Metadata example

Vertex Files

A vertex file contains the data of each vertex. A vertex of data is generated for each behavior. The following shows the format. id is the unique identifier of a set of vertex data.

id, label, property 1, property 2, property 3,...

• The vertex ID cannot contain hyphens (-).
• You do not need to set the vertex ID type. Its default value is string.

Example:

Lethal Weapon, movie, Lethal Weapon, 1987, Action; Comedy; Crime; Drama
Vivian, user, Vivian, F, 25-34, artist, 98133
Eric, user, Eric, M, 18-24, college/grad student, 40205

id 1, id 2, label, property 1, property 2,...

Vivian,Lethal Weapon,rate,5,2000-12-27 23:44:41
Eric,Lethal Weapon,rate,4,2000-11-21 15:33:18
Vivian,Eric,friends