Community
Learn
Tools Library
AI Tools
Leisure
search
English
Article Tags
Home Technical Articles Database Oracle
How to write addition, subtraction, multiplication and division in oracle

How to write addition, subtraction, multiplication and division in oracle

How to write addition, subtraction, multiplication and division in Oracle: 1. For addition operations, you can use the plus sign "+" to implement the code "Column Name 1 + Column Name 2 AS sum"; 2. For subtraction operations, you can use the minus sign "-" to implement the code. "Column name 1 - column name 2 AS difference"; 3. For multiplication operation, you can use the multiplication sign "*", the code is "column name 1*column name 2 AS product"; 4. For division operation, you can use the division sign " /" to achieve, the code "column name 1/column name 2 AS quotient".

Aug 24, 2023 pm 02:25 PM
oracle 加减乘除
How to convert string to date in oracle

How to convert string to date in oracle

You can use the "TO_DATE" function to convert Oracle strings to dates. Use the syntax "TO_DATE(char, format)" of the TO_DATE function to complete the conversion, where char represents the string to be converted to a date, and format represents the date format of the string. ​It should be noted that if the string does not match the specified date format, the TO_DATE function will throw an error. Therefore, make sure to specify the correct date format when using the TO_DATE function for date conversion.

Aug 22, 2023 pm 02:48 PM
oracle
How to clear table data in oracle

How to clear table data in oracle

How to clear table data in Oracle: 1. Use the TRUNCATE TABLE statement to delete all rows in the table, but retain the table structure, indexes, constraints, etc.; 2. Use the DELETE statement to delete rows in the table, and you can Conditionally select rows to be deleted; 3. Use the DROP TABLE statement to delete the entire table, including table structure, indexes, constraints, etc.

Aug 16, 2023 am 11:52 AM
oracle
How to delete table fields

How to delete table fields

Steps to delete table fields: 1. Back up data, you can use database management tools or write scripts to back up data to other places to ensure data security; 2. Check field dependencies, you can query the structure of other tables or find related programs code to confirm whether there is a dependency relationship; 3. To delete a field, first use the ALTER TABLE statement to modify the table structure, and then use the DROP COLUMN statement to delete the field; 4. Check the deletion result. After deleting the field, you need to modify the table structure. verify.

Aug 15, 2023 am 11:14 AM
表字段
What should I do if Oracle does not have a listener?

What should I do if Oracle does not have a listener?

Oracle has no listener solution: 1. Confirm whether the listener configuration is correct and ensure that the name and port number of the listener matches the database instance; 2. Use the lsnrctl command to start the listener; 3. Use the lsnrctl command to check the status of the listener; 4 , use the alter command to register the database instance to the listener; 5. Check the firewall settings on the server to ensure that access to the listener port is allowed; 6. Check whether the network connection is normal; 7. View the listener log file to find any errors or warnings News; 8. Seek professional support.

Aug 10, 2023 pm 01:50 PM
oracle 监听器（Watchers）
Can Oracle duplicate indexes?

Can Oracle duplicate indexes?

Oracle cannot duplicate indexes. In Oracle database, creating duplicate indexes is not allowed and will cause an error. Duplicate indexes may cause the following problems: 1. Waste of storage space, which will increase the storage requirements of the database and may lead to performance degradation; 2. Increase maintenance costs. When adding, deleting, or modifying operations on the table, the database needs to update all related indexes. , with duplicate indexes, the update operation will become more complex and time-consuming; 3. Reduced performance, with duplicate indexes, the database may select the wrong index, resulting in reduced query performance.

Aug 07, 2023 pm 03:00 PM
oracle
What should I do if Oracle cannot export an empty table?

What should I do if Oracle cannot export an empty table?

Oracle empty table cannot be exported. Solution: 1. Grant the current user permissions; 2. Try to reconnect to the database, or check whether the database connection string is correct; 3. Check whether the table exists. If the table does not exist, you can create the table and then proceed. Export; 4. Try to use other export tools, or update the version of the currently used export tool; 5. Check the database configuration, especially the export-related parameter configuration; 6. Use the CREATE TABLE AS SELECT statement to export data; 7. Use data pump The tool exports an empty table.

Aug 07, 2023 pm 02:38 PM
oracle
What to do if Oracle11g physical memory fails

What to do if Oracle11g physical memory fails

Oracle11g physical memory failure solution: 1. Ensure that the physical memory size of the system meets the minimum requirements; 2. Check the memory allocation parameters, check whether the parameter settings are reasonable and match the system physical memory; 3. Check the operating system resource limits, use the ulimit command to view and modify resource limits; 4. Check the database load and consider optimizing queries, adding hardware resources or spreading the load; 5. Check the database configuration, and if it is unreasonable, make adjustments as needed; 6. If the above steps cannot solve the problem, contact Oracle support.

Aug 07, 2023 pm 02:28 PM
oracle
Detailed explanation of oracle substr function usage

Detailed explanation of oracle substr function usage

Oracle substr function usage: 1. To extract the entire string, you can set start_position to 1 and length to the string length; 2. To extract the substring, you can specify the values ​​of start_position and length; 3. To extract the substring starting from the specified position For strings, you can set the length value to the length of the string minus start_position plus 1; 4. Extract the last few characters; 5. Extract the substring from the specified position to the end of the string, etc.

Aug 04, 2023 pm 03:49 PM
oracle substr
oracle query primary key

oracle query primary key

Oracle is a commonly used relational database management system that supports the efficient operation of large enterprise-level applications. When using Oracle to query, it is often necessary to query the primary key of the table to ensure the uniqueness and integrity of the data. This article will introduce how to query the primary key in Oracle. 1. What is a primary key? In a relational database, each table has a primary key, which is used to identify and uniquely distinguish each row of data in the table. The primary key has the characteristics of uniqueness, non-nullity and stability in the table. The primary key can be a single column or a combination of columns, and the primary key value

May 18, 2023 pm 03:48 PM
oracle modify table data

oracle modify table data

Oracle is currently one of the most widely used enterprise-level database management systems in the world. Its powerful data operation and management functions have attracted the favor of many enterprises. In Oracle, modifying table data is a very common operation. In this article, we will take an in-depth look at how to modify table data using Oracle. 1. Overview In Oracle, modifying table data can be achieved through the SQL command UPDATE. The UPDATE command can modify one or more records in the table. The syntax of the UPDATE command is as follows: UPDATE table name S

May 18, 2023 pm 02:41 PM
oracle monitoring cannot be started

oracle monitoring cannot be started

Oracle is a commonly used database management system, and Oracle monitoring is an important component for realizing communication between the client and the server. It plays a pivotal role in connecting to the database. Therefore, once the monitoring cannot be started, it will greatly affect the use and use of the database. run. Many times, various errors will occur when we start Oracle database monitoring. This article will describe the reasons and solutions for why Oracle database monitoring cannot be started. 1. Reasons why Oracle monitoring cannot be started 1. The listening program port is occupied. Oracle monitoring is through monitoring.

May 18, 2023 pm 02:00 PM
oracle linux system installation

oracle linux system installation

Oracle Linux system installation Oracle Linux is an operating system based on Red Hat Enterprise Linux. It has a high degree of stability and security and is one of the preferred operating systems in enterprise-level applications and database environments. Here, we will introduce you how to install Oracle Linux system on your computer. 1. Download Oracle Linux. First, visit Oracle’s official website (http://www.oracle.com/t

May 18, 2023 pm 01:48 PM
oracle number conversion string

oracle number conversion string

Oracle database is a widely used relational database management system. In Oracle, converting numbers and strings to and from each other is a common operation. The process of converting numbers to strings requires the use of two functions: TO_CHAR and CAST functions. The TO_CHAR function is the most basic way to convert a number to a string in Oracle. The syntax format of this function is as follows: TO_CHAR(number,[format_mask],[nls_language]) where number means to convert

May 18, 2023 pm 01:35 PM

Hot tools Tags

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

Video Face Swap

Video Face Swap

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

Hot Article

What's New in Windows 11 KB5054979 & How to Fix Update Issues
3 weeks ago By DDD
How to fix KB5055523 fails to install in Windows 11?
2 weeks ago By DDD
InZoi: How To Apply To School And University
3 weeks ago By DDD
How to fix KB5055518 fails to install in Windows 10?
2 weeks ago By DDD
Roblox: Dead Rails – How To Summon And Defeat Nikola Tesla
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Show More

Hot Tools

vc9-vc14 (32+64 bit) runtime library collection (link below)

vc9-vc14 (32+64 bit) runtime library collection (link below)

Download the collection of runtime libraries required for phpStudy installation

VC9 32-bit

VC9 32-bit

VC9 32-bit phpstudy integrated installation environment runtime library

PHP programmer toolbox full version

PHP programmer toolbox full version

Programmer Toolbox v1.0 PHP Integrated Environment

VC11 32-bit

VC11 32-bit

VC11 32-bit phpstudy integrated installation environment runtime library

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Show More

Hot Topics

Where is the login entrance for gmail email?
7798
15
Java Tutorial
1644
14
CakePHP Tutorial
1402
52
Laravel Tutorial
1299
25
PHP Tutorial
1234
29
Show More