Home Database Mysql Tutorial Oracle中INSTR,SUBSTR方法

Oracle中INSTR,SUBSTR方法

Jun 07, 2016 pm 04:55 PM
oracle number

INSTR方法的格式为 INSTR(源字符串, 目标字符串, 起始位置, 匹配序号) 例如:INSTR(

INSTR方法的格式为
INSTR(源字符串, 目标字符串, 起始位置, 匹配序号)

例如:INSTR('CORPORATE FLOOR','OR', 3, 2)中,,源字符串为'CORPORATE FLOOR', 目标字符串为'OR',起始位置为3,取第2个匹配项的位置。

默认查找顺序为从左到右。当起始位置为负数的时候,从右边开始查找。

所以SELECT INSTR('CORPORATE FLOOR', 'OR', -1, 1) "Instring" FROM DUAL的显示结果是

Instring
——————
14


Oracle的substr函数的用法
取得字符串中指定起始位置和长度的字符串   substr( string, start_position, [ length ] )
如:
     substr('This is a test', 6, 2)     would return 'is'
     substr('This is a test', 6)     would return 'is a test'
     substr('TechOnTheNet', -3, 3)     would return 'Net'
     substr('TechOnTheNet', -6, 3)     would return 'The'select substr('Thisisatest', -4, 2) value from dual

linux

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How long will Oracle database logs be kept? How long will Oracle database logs be kept? May 10, 2024 am 03:27 AM

The retention period of Oracle database logs depends on the log type and configuration, including: Redo logs: determined by the maximum size configured with the "LOG_ARCHIVE_DEST" parameter. Archived redo logs: Determined by the maximum size configured by the "DB_RECOVERY_FILE_DEST_SIZE" parameter. Online redo logs: not archived, lost when the database is restarted, and the retention period is consistent with the instance running time. Audit log: Configured by the "AUDIT_TRAIL" parameter, retained for 30 days by default.

The order of the oracle database startup steps is The order of the oracle database startup steps is May 10, 2024 am 01:48 AM

The Oracle database startup sequence is: 1. Check the preconditions; 2. Start the listener; 3. Start the database instance; 4. Wait for the database to open; 5. Connect to the database; 6. Verify the database status; 7. Enable the service (if necessary ); 8. Test the connection.

Oracle database server hardware configuration requirements Oracle database server hardware configuration requirements May 10, 2024 am 04:00 AM

Oracle database server hardware configuration requirements: Processor: multi-core, with a main frequency of at least 2.5 GHz. For large databases, 32 cores or more are recommended. Memory: At least 8GB for small databases, 16-64GB for medium sizes, up to 512GB or more for large databases or heavy workloads. Storage: SSD or NVMe disks, RAID arrays for redundancy and performance. Network: High-speed network (10GbE or higher), dedicated network card, low-latency network. Others: Stable power supply, redundant components, compatible operating system and software, heat dissipation and cooling system.

How much memory does oracle require? How much memory does oracle require? May 10, 2024 am 04:12 AM

The amount of memory required by Oracle depends on database size, activity level, and required performance level: for storing data buffers, index buffers, executing SQL statements, and managing the data dictionary cache. The exact amount is affected by database size, activity level, and required performance level. Best practices include setting the appropriate SGA size, sizing SGA components, using AMM, and monitoring memory usage.

Oracle scheduled tasks execute the creation step once a day Oracle scheduled tasks execute the creation step once a day May 10, 2024 am 03:03 AM

To create a scheduled task in Oracle that executes once a day, you need to perform the following three steps: Create a job. Add a subjob to the job and set its schedule expression to "INTERVAL 1 DAY". Enable the job.

How much memory is needed to use oracle database How much memory is needed to use oracle database May 10, 2024 am 03:42 AM

The amount of memory required for an Oracle database depends on the database size, workload type, and number of concurrent users. General recommendations: Small databases: 16-32 GB, Medium databases: 32-64 GB, Large databases: 64 GB or more. Other factors to consider include database version, memory optimization options, virtualization, and best practices (monitor memory usage, adjust allocations).

How to read dbf file in oracle How to read dbf file in oracle May 10, 2024 am 01:27 AM

Oracle can read dbf files through the following steps: create an external table and reference the dbf file; query the external table to retrieve data; import the data into the Oracle table.

How much memory does an oracle database require? How much memory does an oracle database require? May 10, 2024 am 02:09 AM

Oracle Database memory requirements depend on the following factors: database size, number of active users, concurrent queries, enabled features, and system hardware configuration. Steps in determining memory requirements include determining database size, estimating the number of active users, understanding concurrent queries, considering enabled features, and examining system hardware configuration.

See all articles