


How Can I Efficiently Match Large String Lists Against an Oracle Database Table?
Efficient matching of large string lists in Oracle database
In Oracle SQL Developer, matching with database tables using large lists of strings can be challenging, especially if permissions are restricted. To overcome this problem, consider the following techniques:
Collections
Leverage collections to efficiently store and manipulate large numbers of values in memory. By creating a SYS.ODCIVARCHAR2LIST
collection you can load your list of IDs and perform join operations using nested queries.
VARIABLE cursor REFCURSOR; DECLARE your_collection SYS.ODCIVARCHAR2LIST := SYS.ODCIVARCHAR2LIST(); BEGIN your_collection.EXTEND( 10000 ); FOR i IN 1 .. 10000 LOOP -- 填充集合。 your_collection(i) := DBMS_RANDOM.STRING( 'x', 20 ); END LOOP; OPEN :cursor FOR SELECT t.* FROM your_table t INNER JOIN TABLE( your_collection ) c ON t.id = c.COLUMN_VALUE; END; /
Java method
For greater flexibility, you can use Java to handle collections and query execution. This approach involves creating an ARRAY object and passing it to the prepared statement.
import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import oracle.jdbc.OraclePreparedStatement; import oracle.sql.ARRAY; import oracle.sql.ArrayDescriptor; public class TestDatabase2 { public static void main(String args[]){ try{ Class.forName("oracle.jdbc.OracleDriver"); Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE","username","password"); String[] ids = { "1", "2", "3" }; ArrayDescriptor des = ArrayDescriptor.createDescriptor("SYS.ODCIVARCHAR2LIST", con); PreparedStatement st = con.prepareStatement("SELECT t.* FROM your_table t INNER JOIN TABLE( ? ) c ON t.id = c.COLUMN_VALUE"); // 将数组传递给过程 - ((OraclePreparedStatement) st).setARRAYAtName( "your_collection", new ARRAY( des, con, ids ) ); ResultSet cursor = st.executeQuery(); while ( cursor.next() ) { int id = cursor.getInt(1); double column1 = cursor.getDouble(2); double column2 = cursor.getDouble(3); System.out.println( String.format( "Id: %5d", id ) ); System.out.println( String.format( " Column1: %s", column1 ) ); System.out.println( String.format( " Column2: %s", column2 ) ); } } catch(ClassNotFoundException | SQLException e) { System.out.println(e); } } }
Even with read-only permissions, these methods provide efficient solutions for matching large string lists using Oracle databases.
Please note that the setARRAYAtName
method in the Java example uses a placeholder ?
instead of the hardcoded collection name "your_collection", which is more in line with best practices. Additionally, the actual database connection string, username, and password need to be replaced with your actual values.
The above is the detailed content of How Can I Efficiently Match Large String Lists Against an Oracle Database Table?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











Full table scanning may be faster in MySQL than using indexes. Specific cases include: 1) the data volume is small; 2) when the query returns a large amount of data; 3) when the index column is not highly selective; 4) when the complex query. By analyzing query plans, optimizing indexes, avoiding over-index and regularly maintaining tables, you can make the best choices in practical applications.

MySQL is an open source relational database management system. 1) Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2) Basic operations: INSERT, UPDATE, DELETE and SELECT. 3) Advanced operations: JOIN, subquery and transaction processing. 4) Debugging skills: Check syntax, data type and permissions. 5) Optimization suggestions: Use indexes, avoid SELECT* and use transactions.

MySQL is suitable for beginners because it is simple to install, powerful and easy to manage data. 1. Simple installation and configuration, suitable for a variety of operating systems. 2. Support basic operations such as creating databases and tables, inserting, querying, updating and deleting data. 3. Provide advanced functions such as JOIN operations and subqueries. 4. Performance can be improved through indexing, query optimization and table partitioning. 5. Support backup, recovery and security measures to ensure data security and consistency.

The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.

MySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.

InnoDB uses redologs and undologs to ensure data consistency and reliability. 1.redologs record data page modification to ensure crash recovery and transaction persistence. 2.undologs records the original data value and supports transaction rollback and MVCC.

MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen

MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.
