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GRAPH_ID_FROM_EDGE_ID (Transact-SQL)

  • Článok

Applies to: SQL Server 2017 (14.x) and later Azure SQL Database Azure SQL Managed Instance

Returns the internal graph ID for a given edge ID.

Syntax

GRAPH_ID_FROM_EDGE_ID ( edge_id )

Arguments

edge_id

The character representation (JSON) of the $edge_id pseudo-column in an edge table.

Return value

Returns the internal graph ID, which is a bigint.

Remarks

  • Owing to the performance overhead of parsing and validating the supplied character representation (JSON) of edges, you should only use GRAPH_ID_FROM_EDGE_ID where needed. In most cases, MATCH should be sufficient for queries over graph tables.
  • For GRAPH_ID_FROM_EDGE_ID to return a value, the supplied character JSON must be valid and the named schema.table within the JSON, must be a valid edge table.
  • If a graph ID is returned by the function, it's only guaranteed that it will be a valid integer. No checks are made whether the graph ID is present in the edge table.
  • The data type and behavior of graph IDs are implementation specific details, and are subject to change. For example, you shouldn't assume that graph IDs in a given edge table are sequential.

Examples

The following example returns the internal graph ID for the edges in the friendOf edge table.

SELECT GRAPH_ID_FROM_EDGE_ID($edge_id)
FROM friendOf;

Here are the results:

...
25073
98943
69725
68781
30354
...

See also