Bindresult

Bindresult is a term used in database access layers to describe the process of associating the columns of a query’s result set with program variables or buffers. This binding enables a program to read values directly into pre-allocated storage as rows are fetched, typically within the context of prepared statements where the structure of the result is known in advance.

In practice, the workflow usually involves preparing a statement, allocating or declaring variables to hold the result data, binding these variables to the result columns, executing the statement, and then fetching each row. When a row is fetched, the bound variables automatically receive the corresponding column values. The approach can reduce data copying and improve clarity by keeping result handling close to the data access code.

The exact API and naming vary by language and library. For example, some environments expose a function named bind_result or bind_result-like to establish the bindings. In PHP’s mysqli extension, a function such as mysqli_stmt_bind_result binds result columns to PHP variables. In the MySQL C API for prepared statements, a function like mysql_stmt_bind_result serves a similar purpose by binding buffers to the statement’s result columns. Bindresult is conceptually distinct from binding input parameters, which attach values to placeholders in the prepared statement rather than to the output.

Common considerations include ensuring the number and order of bound variables match the result columns, matching types to avoid conversion issues, and properly handling NULL values. Mismatches or uninitialized bindings can lead to runtime errors or incorrect data retrieval.

See also: prepared statements, parameter binding, fetch methods, result handling.