In Java, the 'PreparedStatement' interface is a sub interface which is used to execute __________ query.
Parameterized
Understanding Java's PreparedStatement Interface
The question asks about the type of database query executed by Java's PreparedStatement interface. This interface is a key part of Java Database Connectivity (JDBC) API, used for interacting with databases.
The primary purpose and feature of PreparedStatement is its ability to handle parameterized SQL queries. Parameterized queries are SQL statements where placeholders are used instead of directly embedding literal values. These placeholders are then filled in later with actual values.
Why PreparedStatement is Used for Parameterized Queries
- Security: Using placeholders prevents SQL injection vulnerabilities. The database server understands that the values provided for the parameters are data, not executable SQL code.
- Performance: The database can parse and compile the SQL statement once, even if it's executed multiple times with different parameter values. This can improve performance for frequently executed queries.
- Readability and Usability: It makes constructing SQL queries with dynamic values cleaner and less error-prone compared to manually concatenating strings.
Let's look at the options:
- Parameterized: This is the correct answer.
PreparedStatementis specifically designed for executing parameterized queries by setting values for placeholders (like?). - Executable: All SQL queries that are sent to the database via JDBC are intended to be executable. This term doesn't distinguish the specific feature of
PreparedStatement. - Low level: While JDBC is arguably lower level than some ORMs,
PreparedStatementitself isn't characterized by being 'low level' compared to other JDBC interfaces likeStatement; it's a specific interface for a specific type of query handling. - Simple:
PreparedStatementcan be used for simple queries, but its main advantage comes into play with queries that involve dynamic values, which can be complex. It's not limited to just 'simple' queries.
Therefore, the most accurate description of the type of query PreparedStatement is primarily used to execute is a parameterized query.
Revision Table: Java PreparedStatement vs Statement
| Feature | Statement | PreparedStatement |
|---|---|---|
| Purpose | For executing static SQL statements. | For executing precompiled SQL statements with potential parameters. |
| SQL Injection Risk | High (if values are concatenated into query string) | Low (parameters are handled separately) |
| Performance | Query parsed and compiled each time. | Query potentially parsed and compiled once by the database. |
| Usability | Requires manual string concatenation for dynamic values. | Uses placeholders (?) for dynamic values, set using setter methods (setInt(), setString(), etc.). |
Additional Information: JDBC Interfaces
JDBC provides several interfaces for executing SQL statements:
Statement: Used for executing simple SQL statements without parameters.PreparedStatement: ExtendsStatement. Used for executing precompiled SQL statements with input parameters. This is the preferred choice for executing SQL statements multiple times or statements that accept parameters.CallableStatement: ExtendsPreparedStatement. Used for executing stored procedures and functions.
Using PreparedStatement is generally recommended over Statement for dynamic queries due to the security and performance benefits.
Important Questions from Java
When an applet begins, which of the following sequence methods is CORRECT?
1) start()
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3) init()
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class test
{public static void main (String args [ ])
{
System.out.println(20 + 30 + "Java");
System.out.println("Java" + 20 + 30);
}
}
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