In Oracle database, sometimes it is necessary to convert numeric or date data into string type to facilitate output or string splicing operations. This article will introduce how to convert numeric, date and Boolean data into string types in Oracle database.
1. Convert numeric type to string type
- TO_CHAR function
In Oracle database, the most commonly used method is to convert numeric type to string type. The type of function is the TO_CHAR function, and its syntax is as follows:
TO_CHAR(number, [format], [nls_language])
Among them, number represents the numerical type to be converted, and format represents formatting The template can be a preset format or a custom format. nls_language represents the locale of the data. If this parameter is omitted, the default value of the current session is used. The following are some commonly used formatting templates:
Template Description
FM Delete leading spaces
0 Fill the missing digits with 0
09 Fill the missing digits with 0s, two-digit alignment
9999 Insufficient digits are filled with spaces, aligned to four digits
$9,999 Signed amount, grouped by three digits
Dollar9,999.99 Signed amount, thousands separator and two decimal places
For example, put the number 12345.67 is converted into a string type, the format is currency format, and the US English language environment is used. You can use the following code:
SELECT TO_CHAR(12345.67, '$9,999.99', 'NLS_LANGUAGE=AMERICAN')
FROM dual;
The output result is: $12,345.67.
- CAST function
In addition to the TO_CHAR function, Oracle also provides the CAST function for converting numeric types to string types. The syntax is as follows:
CAST(expression AS data_type)
Among them, expression represents the numerical type to be converted, and data_type represents the target data type to be converted. Here, we can convert the numeric type to CHAR or VARCHAR2 type. For example, to convert the number 12345.67 into a string type, you can use the following code:
SELECT CAST(12345.67 AS VARCHAR2(10))
FROM dual;
The output result is: 12345.67.
2. Convert date type to string type
- TO_CHAR function
In Oracle database, convert date type data to string type in the same way You can use the TO_CHAR function, its syntax is as follows:
TO_CHAR(date, [format], [nls_language])
Among them, date represents the date data to be converted, and format represents the formatted Template, nls_language represents the locale of the data. The following are some commonly used formatting templates:
Template description
YYYY-MM-DD The year, month and day of the date
YYYY-MM-DD HH24:MI:SS The year, month of the date , day, hour, minute and second
MONTH The full name of the month (such as January)
MON The abbreviation of the month (such as Jan)
DD-MON-YYYY The day, month and year of the date (such as 31- JAN-2022)
For example, to convert date type data '2022-01-31' to string type, you can use the following code:
SELECT TO_CHAR('2022-01-31' , 'YYYY-MM-DD')
FROM dual;
The output result is: 2022-01-31.
- CAST function
In addition to the TO_CHAR function, Oracle also provides the CAST function for converting date type data to string type. The syntax is as follows:
CAST(expression AS data_type)
Among them, expression represents the date data to be converted, and data_type represents the target data type to be converted. Here, we can convert date type data to CHAR or VARCHAR2 type. For example, to convert date type data '2022-01-31' to string type, you can use the following code:
SELECT CAST('2022-01-31' AS VARCHAR2(10))
FROM dual;
The output result is: 2022-01-31.
3. Conversion of Boolean type to string type
In Oracle database, Boolean type data cannot be directly converted to string type, but Boolean type data can be converted with the help of CASE expression. The following is a sample code that converts Boolean data to string type:
SELECT
CASE WHEN flag = 'true' THEN 'Yes' WHEN flag = 'false' THEN 'No' END AS result
FROM my_table;
where flag is Boolean data, 'true' and 'false' are string types, and result is the converted string type. If the flag is 'true', it returns 'Yes'; if the flag is 'false', it returns 'No'.
To sum up, this article introduces the method of converting numeric, date and Boolean data into string types in Oracle database. For numeric and date data, we can use the TO_CHAR function or CAST function to achieve conversion; for Boolean data, we can use CASE expressions to achieve conversion.
The above is the detailed content of oracle convert to string. For more information, please follow other related articles on the PHP Chinese website!

Oracle software applications in the real world include e-commerce platforms and manufacturing. 1) On e-commerce platforms, OracleDatabase is used to store and query user information. 2) In manufacturing, OracleE-BusinessSuite is used to optimize inventory and production planning.

The reason why Oracle software shines in multiple fields is its powerful application and customized solutions. 1) Oracle provides comprehensive solutions from database management to ERP, CRM, SCM, 2) its solutions can be customized according to industry characteristics such as finance, medical care, manufacturing, etc. 3) Successful cases include Citibank, Mayo Clinic and Toyota, 4) The advantages lie in comprehensiveness, customization and scalability, but challenges include complexity, cost and integration issues.

Choosing MySQL or Oracle depends on project requirements: 1. MySQL is suitable for small and medium-sized applications and Internet projects because of its open source, free and ease of use; 2. Oracle is suitable for core business systems of large enterprises because of its powerful, stable and advanced functions, but at a high cost.

Oracle's product ecosystem includes databases, middleware and cloud services. 1. OracleDatabase is its core product, supporting efficient data storage and management. 2. Middleware such as OracleWebLogicServer connects to different systems. 3. OracleCloud provides a complete set of cloud computing solutions.

MySQL and Oracle each have advantages in performance, scalability, and security. 1) Performance: MySQL is suitable for read operations and high concurrency, and Oracle is good at complex queries and big data processing. 2) Scalability: MySQL extends through master-slave replication and sharding, and Oracle uses RAC to provide high availability and load balancing. 3) Security: MySQL provides fine-grained permission control, while Oracle has more comprehensive security functions and automation tools.

Oracle is called the "Powerhouse" of database management because of its high performance, reliability and security. 1. Oracle is a relational database management system that supports multiple operating systems. 2. It provides a powerful data management platform with scalability, security and high availability. 3. Oracle's working principles include data storage, query processing and transaction management, and supports performance optimization technologies such as indexing, partitioning and caching. 4. Examples of usage include creating tables, inserting data, and writing stored procedures. 5. Performance optimization strategies include index optimization, partition table, cache management and query optimization.

Oracleoffersacomprehensivesuiteofproductsandservicesincludingdatabasemanagement,cloudcomputing,enterprisesoftware,andhardwaresolutions.1)OracleDatabasesupportsvariousdatamodelswithefficientmanagementfeatures.2)OracleCloudInfrastructure(OCI)providesro

The development history of Oracle software from database to cloud computing includes: 1. Originated in 1977, it initially focused on relational database management system (RDBMS), and quickly became the first choice for enterprise-level applications; 2. Expand to middleware, development tools and ERP systems to form a complete set of enterprise solutions; 3. Oracle database supports SQL, providing high performance and scalability, suitable for small to large enterprise systems; 4. The rise of cloud computing services further expands Oracle's product line to meet all aspects of enterprise IT needs.


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

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

Dreamweaver CS6
Visual web development tools

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.