parameterIndex

The term parameterIndex is commonly encountered in programming, particularly within database interaction contexts such as JDBC (Java Database Connectivity). It refers to the position of a parameter placeholder within a SQL statement that is being prepared for execution. SQL statements often contain placeholders, denoted by question marks (?), which are used to substitute dynamic values, preventing SQL injection vulnerabilities and improving performance through query plan reuse.

When a statement is prepared with these placeholders, each placeholder is assigned a numerical index starting from 1. The first placeholder in the SQL string is parameterIndex 1, the second is parameterIndex 2, and so on. When executing the prepared statement, the programmer must provide the actual values to be bound to these parameters, and these values must be associated with their corresponding parameterIndex. For example, in Java's JDBC API, methods like `preparedStatement.setInt(int parameterIndex, int x)` or `preparedStatement.setString(int parameterIndex, String x)` are used to bind values to specific parameter positions. Understanding parameterIndex is crucial for correctly constructing and executing dynamic SQL queries in a safe and efficient manner.

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