69 lines
2.2 KiB
Plaintext
69 lines
2.2 KiB
Plaintext
== Why is this an issue?
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Executing a batch of SQL queries instead of individual queries improves performance by reducing communication overhead with the database.
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Batching SQL statements is beneficial in common situations where a SQL statement is executed within a loop.
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In such cases, adding the statement to a batch and subsequently executing it reduces the number of interactions with the database.
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This results in improved efficiency and faster execution times.
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The rule raises an issue when it detects a `java.sql.Statement` being executed within a loop instruction, such as `for`, `while` or the `forEach` method of `java.lang.Iterable`, `java.util.Map` and `java.util.stream.Stream`.
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== How to fix it
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Group SQL statements by using the method `addBatch` to add them to a batch and then execute them using `executeBatch` to send them to the database in a single call.
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=== Code examples
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==== Noncompliant code example
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[source,java,diff-id=1,diff-type=noncompliant]
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----
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public void execute(Connection connection) {
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try {
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Statement statement = connection.createStatement();
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for (int i = 0; i < 10; i++) {
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statement.execute("INSERT INTO myTable (column1, column2) VALUES (" + i + ", 'value" + i + "')"); // Noncompliant
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}
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statement.close();
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connection.close();
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} catch (SQLException e) {
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e.printStackTrace();
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}
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}
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----
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==== Compliant solution
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[source,java,diff-id=1,diff-type=compliant]
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----
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public void execute(Connection connection) {
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try {
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Statement statement = connection.createStatement();
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for (int i = 0; i < 10; i++) {
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statement.addBatch("INSERT INTO myTable (column1, column2) VALUES (" + i + ", 'value" + i + "')"); // Compliant
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}
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statement.executeBatch();
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statement.close();
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connection.close();
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} catch (SQLException e) {
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e.printStackTrace();
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}
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}
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----
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== Resources
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=== Documentation
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* https://docs.oracle.com/en/java/javase/21/docs/api/java.sql/java/sql/Statement.html[Oracle Java SE 21 API - java.sql.Statement]
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* https://docs.oracle.com/en/java/javase/21/docs/api/java.sql/java/sql/PreparedStatement.html[Oracle Java SE 21 API - java.sql.PreparedStatement]
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=== Articles & blog posts
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* https://www.baeldung.com/jdbc-batch-processing[Baeldung - JDBC Batch Processing]
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