Ergebnisse filtern und sortieren

When working with large graphs, you often need to find very specific information or present it in a particular order.

• Filtering helps you narrow down results to only what's relevant.
• Ordering helps you sort your results for better readability or analysis.

In this lesson, we'll master the WHERE and ORDER BY clauses in Cypher.

The WHERE clause is used to filter patterns or properties based on specific conditions. It typically comes after a MATCH clause.

Think of it like saying: "Find me all people, WHERE their birth year is 1970."

You can use various comparison operators in your WHERE clause:

• = (equal to)
• <> (not equal to)
• > (greater than)
• < (less than)
• >= (greater than or equal to)
• <= (less than or equal to)

Let's find movies released after the year 2000.

Combine multiple conditions using logical operators:

• AND: Both conditions must be true.
• OR: At least one condition must be true.
• XOR: Exactly one condition must be true.
• NOT: Negates a condition.

Find people born between 1970 and 1980 (inclusive).

Cypher offers powerful operators for string matching and list containment:

• CONTAINS, STARTS WITH, ENDS WITH for partial string matches.
• IN to check if a property value is within a list of values.

Let's find specific actors by name using IN.

The ORDER BY clause sorts your query results. It comes after RETURN (or WITH).

By default, results are sorted in ascending order (smallest to largest, A-Z).

You can explicitly specify the sort direction:

• ASC: Ascending (A-Z, 0-9). This is the default.
• DESC: Descending (Z-A, 9-0).

Let's sort movies by their release year, from newest to oldest.

You can sort by multiple properties. The order in which you list them in ORDER BY matters.

Cypher will first sort by the first property, then by the second for any ties in the first, and so on.

Sort people by birth year (ascending), and then by name (ascending) for those born in the same year.

A typical Cypher query flow often involves:

1. MATCH: Find the graph pattern.
2. WHERE: Filter the matched patterns.
3. RETURN: Select the data you want.
4. ORDER BY: Sort the returned data.

Find actors born before 1970, order them by name (descending), then by the movie title they acted in (ascending).

Which Cypher query correctly finds movies released after 1999 and orders them by title in descending order?

Great job! You've learned how to precisely control your Cypher query results:

• The WHERE clause filters data based on conditions.
• The ORDER BY clause sorts your results in ascending or descending order.
• You can combine these with comparison, logical, and string/list operators for powerful filtering.

Next, we'll explore how to summarize and reshape your data with Aggregation and Projections!