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.
Inserts, Updates, Deletes and Upserts
- Insert simple data
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Inserting set data with the INSERT command.
- Collection - Set
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Unordered list of items of same data type.
- Collection - List
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Ordered list of items of same data type.
- Collection - Map
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List of key-value pairs.
- Tuple
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Ordered list of items of possibly different data types.
- User-defined type (UDT)
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Insert data into a user-defined type.
- Lightweight transactions (LWTs)
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INSERT and UPDATE statements that use the IF clause support lightweight transactions, also known as Compare and Set (CAS).
- Batch inserts and updates
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Perform multiple writes in the same command.
- JSON-formatted values
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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
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Inserting data with the cqlsh command COPY from a CSV file is common for testing queries.
- Deleting values from a column or entire row
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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
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Use time-to-live (TTL) to expire data in a column or table.