Inserting and updating data
Data can be inserted or updated into tables. Many different types of data can be stored in CQL tables.
Inserting and updating data in Cassandra is really the same thing. Data can be upserted, meaning that the previously stored data is deleted and replaced with the updated data.
- Insert simple data
Inserting set data with the INSERT command.
- Collection - Set
Unordered list of items of same data type.
- Collection - List
Ordered list of items of same data type.
- Collection - Map
List of key-value pairs.
Ordered list of items of possibly different data types.
- User-defined type (UDT)
Insert data into a user-defined type.
- Lightweight transactions (LWTs)
INSERT and UPDATE statements that use the IF clause support lightweight transactions, also known as Compare and Set (CAS).
- Batch inserts and updates
Perform multiple writes in the same command.
- JSON-formatted values
Inserting JSON data with the INSERT command for testing queries. Starting with DataStax Enterprise 5.0, JSON data can be inserted.
- Importing data from a CSV file
Inserting data with the cqlsh command COPY from a CSV file is common for testing queries.
- Deleting values from a column or entire row
Use the DELETE statement to replace the value in a column with null or to remove an entire row of data.
- Expiring data with time-to-live
Use time-to-live (TTL) to expire data in a column or table.