The last article mainly introduced the commonly used commands of Neo4j CQL, this article mainly introduced its commonly used functions. Follow the column "Knowledge Graph Series" to learn more about knowledge graphs~
table of Contents
Two, AGGREGATION aggregate function
Three, the relationship function
One, string function
Like SQL, Neo4J CQL provides a set of String functions for obtaining desired results in CQL queries. The list of commonly used string functions is as follows:
1.1 UPPER function
Convert letters to uppercase, the syntax is:
UPPER (<input-string>)Among them, <input-string> can be the attribute name of the node or relationship from the Neo4J database.
1.2 LOWER function
Convert letters to lowercase letters, the syntax is:
LOWER (<input-string>)1.3 SUBSTRING function
String interception function, the interception range is left closed and right open, the syntax is as follows:
SUBSTRING(<input-string>,<startIndex> ,<endIndex>)Two, AGGREGATION aggregate function
Neo4j CQL provides some aggregate functions used in the RETURN clause, which is similar to the GROUP BY clause in SQL. The commonly used aggregate functions are as follows:
2.1 COUNT function
It gets the result from the MATCH clause, counts the number of rows that appear in the result, and returns the count value. The syntax is as follows:
COUNT(<value>)2.2 MAX function
Maximum value function, the syntax is:
MAX(<property-name>)2.3 MIN function
The minimum value function, the syntax is:
MIN(<property-name>)2.4 AVG function
Average function, the syntax is:
AVG(<property-name>)2.5 SUM function
The sum function, the syntax is:
SUM(<property-name>)Three, the relationship function
Neo4j CQL provides a set of relationship functions to know the details of the relationship when getting the start node, end node and other details. The commonly used relational functions are as follows:
This article has come to an end, this article mainly describes some Neo4j CQL commonly used functions. What problems did you encounter in the process, welcome to leave a message, let me see what problems you all encountered~