Cursor
A database cursor is an object or interface that executes database operations and incrementally retrieves or traverses their result rows.
A Pythonic Adventure: From Python basics to a working web app
A database cursor is an object that executes database statements and retrieves their results.
- How it is used
- Uses a cursor to execute SQL commands while connecting a Flask application to a SQLite orders database.
- How deep it goes
- Defines the cursor through an analogy and demonstrates creation and execution, while explicitly deferring deeper details.
- Examples
- Demonstrates CREATE TABLE, INSERT orders, and SELECT-based retrieval in an order-tracking application.
- What you can do after
- Operate/configure a cursor to execute table-creation, insertion, and selection commands in a SQLite-backed Flask application.
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Learn SQL in a Month of Lunches
A database cursor is a database programming construct that enables query-result data to be processed one row at a time.
- How it is used
- Processes SELECT results one row at a time when individual evaluation or per-row procedure calls are required.
- How deep it goes
- Explains the DECLARE, OPEN, FETCH, and CLOSE lifecycle through a complete stored-procedure loop and end-of-results handler.
- Examples
- Uses order IDs to total quantities sold at list price and scenarios involving California orders, first orders, and customer messages.
- What you can do after
- Evaluate/understand cursor-based stored procedures and decide when a set-based query can replace row-by-row processing.
Practices of the Python Pro
A database cursor is an object that executes database statements and provides access to their results.
- How it is used
- Executes SQL statements and exposes query results within a reusable persistence-layer helper.
- How deep it goes
- Defines cursor behavior, demonstrates execution and transactions, and stops short of explaining cursor internals.
- Examples
- Uses a DatabaseManager._execute method to run parameterized SQL through a cursor.
- What you can do after
- Build reusable SQLite statement execution that returns query results and supports parameter values.
Coding with AI
A database cursor is an object that executes database statements and accesses their results through an established connection.
- How it is used
- Uses cursors to connect Flask route handlers and model methods to SQLite queries and returned page data.
- How deep it goes
- Explains cursor creation, query use, dependency passing, and connection cleanup, but stops short of database-driver internals.
- Examples
- Demonstrates selecting records, fetching questions, rendering results, generating question sets, and correcting cursor-related import and constructor errors.
- What you can do after
- Operate/configure database-backed Flask code by passing a live cursor into models, fetching records, and closing connections safely.
API Design Patterns
A cursor is a position marker that identifies the point from which the next portion of paged data should be retrieved.
- How it is used
- Guides consumers through collection pages or chunks of a large resource.
- How deep it goes
- Defines termination, opacity, empty-page behavior, and large-resource continuation, without specifying one token representation.
- Examples
- Uses multi-page resource retrieval, empty-result responses, and chunked attachment reads.
- What you can do after
- Operate pagination by passing returned tokens and stopping only when the next token is empty.
MongoDB 8.0 in Action, Third Edition
A cursor is an object representing an incremental result set from a database query and providing methods for traversing its documents.
- How it is used
- Handles large query results through incremental, batched retrieval and supports automatic or manually controlled document traversal.
- How deep it goes
- Explains cursor creation, batching, lazy loading, automatic display, manual iteration, and read timeouts without detailing driver internals.
- Examples
- Uses routes queries, mongosh display behavior, manualIteration(), and a sample_mflix change-stream cursor.
- What you can do after
- Apply it via mongosh to retrieve query results incrementally, choose manual traversal, and monitor change-stream events.
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Python Concurrency with asyncio
A database cursor is an object that traverses and retrieves rows from a database query result, potentially incrementally.
- How it is used
- Streams large PostgreSQL query results when pagination or full-result loading creates memory, query, or database-load concerns.
- How deep it goes
- Explains pointer-style traversal, asynchronous iteration, prefetching, skipping, and batching, but not cursor internals.
- Examples
- Uses a product query to stream 1,000 rows, skip 500 rows, fetch 100, or print the first five.
- What you can do after
- Operate/configure asyncpg cursors inside transactions to stream, skip, batch, and limit retrieved rows.
Related concepts
- closehas part · Close is an operation that terminates access to an associated resource or interface and releases or finalizes related resources or pending work.
- find()produced by · find() is a MongoDB Query API method that returns a cursor for documents matching an optional query filter in a collection.
- loopuses · A loop is a programming control-flow construct that repeatedly executes a block of instructions according to an iteration rule or continuation condition.
- stored procedureused by · A stored procedure is a named executable routine stored in and invoked by a database management system to perform database operations.
- SQLuses · SQL is a standardized declarative language for defining, querying, and manipulating data and structures in relational database systems.
- database result setuses · A database result set is the collection of rows and values produced by evaluating a database query.
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