Inserting an Array to a table in SAP HANA database

As far as I know, there is no direct way of inserting an Array using SQL query in SAP HANA. You will first have to combine the columns (EMPL_Id + Skill Id) using the code and then do a bulk insert to the database.

Array to Table Insert Methods

In SAP HANA, when you need to insert array data into a table, you have several approaches to handle this limitation ?

Method 1: Using UNNEST Function

The UNNEST function can convert an array into individual rows, which can then be inserted into a table ?

-- Create a table first
CREATE TABLE employee_skills (
    empl_id INT,
    skill_id INT
);

-- Insert array data using UNNEST
INSERT INTO employee_skills 
SELECT 101, skill_id 
FROM UNNEST(ARRAY[1, 2, 3, 4]) AS t(skill_id);

Method 2: Application-Level Processing

Process the array in your application code and perform bulk insert operations ?

# Python example for bulk insert
import hdbcli.dbapi

# Sample array data
employee_skills = [(101, 1), (101, 2), (101, 3), (102, 1), (102, 4)]

# Bulk insert using executemany
cursor.executemany(
    "INSERT INTO employee_skills (empl_id, skill_id) VALUES (?, ?)",
    employee_skills
)

Method 3: Dynamic SQL Generation

Generate multiple INSERT statements from your array data ?

-- Multiple INSERT statements
INSERT INTO employee_skills VALUES (101, 1);
INSERT INTO employee_skills VALUES (101, 2);
INSERT INTO employee_skills VALUES (101, 3);
-- Continue for all array elements

Best Practices

When working with array-to-table insertions in SAP HANA ?

• Use bulk insert operations for better performance
• Consider using stored procedures for complex array processing
• Validate array data before insertion to maintain data integrity
• Use prepared statements to avoid SQL injection risks

Conclusion

While SAP HANA doesn't support direct array insertion via SQL, you can effectively insert array data using UNNEST functions, application-level processing, or dynamic SQL generation techniques.