current location：Home > Technical Articles > Database > SQL
- Direction：
- All web3.0 Backend Development Web Front-end Database Operation and Maintenance Development Tools PHP Framework Common Problem Other Tech CMS Tutorial Java System Tutorial Computer Tutorials Hardware Tutorial Mobile Tutorial Software Tutorial Mobile Game Tutorial
- Classify：
-
- What is the usage of exists in oracle?
- Usage of exists in oracle: exists is followed by a subquery, the purpose is to check whether the result of the subquery is true. If the subquery is true, the outer sql statement is executed. exists does not return data, only true or false.
- SQL 8191 2020-05-09 13:17:15
-
- What is the full Chinese name of sql?
- The full Chinese name of sql is Structured Query Language. It is a special-purpose programming language, a database query and programming language, used to access data and query, update and manage relational database systems.
- SQL 21207 2020-05-09 10:44:15
-
- SQL database add, delete, modify, query syntax
- SQL database add, delete, modify and query syntax: 1. [SELECT * FROM table_name]; 2. [INSERT INTO table_name VALUES (value1, value2, value3,...)].
- SQL 8527 2020-05-06 13:34:58
-
- What is wrong with the statements about sql statements?
- Regarding the SQL statement, the error is that "CREATE statement is used to create a table structure and append new records" because the function of the "CREATE" statement is to create a table structure and cannot append new records or append new records. The "INSERT" statement can be used.
- SQL 9632 2020-04-30 10:17:58
-
- Usage of listagg function
- listagg is Oracle's column-to-row function. Its basic usage is "LISTAGG(XXX,XXX) WITHIN GROUP(ORDER BY XXX)", which means splicing together a field of each "Group" through the "Group by" statement.
- SQL 32126 2020-05-06 15:21:07
-
- Oracle method to intercept the first digits of a string
- Oracle can intercept the first few digits of a string through the substr function. The syntax of the substr function is "substr(string,start,length)". Its parameter string represents the specified string to be intercepted. The parameter start specifies where in the string start.
- SQL 50810 2020-04-27 16:37:29
-
- sqlserver2017 installation tutorial
- SQLserver2017 installation tutorial: First load the SQL2017 database image; then select "Installation -> New SQL Server Independent Installation"; then select "Developer Development Edition" and turn off the firewall; finally select the specific required functions and change the installation location.
- SQL 7740 2020-04-27 16:33:01
-
- How to check sa password in sqlserver
- How to check the sa password in sqlserver: first log in to the system using windows identity; then right-click on the service name and select properties; then modify the password in the corresponding position; finally change to sa login and enter the new modified password.
- SQL 30150 2020-03-23 09:13:46
-
- What type of data model does sql server belong to?
- SQL Server is a relational data model; SQL Server is a comprehensive database platform that uses integrated business intelligence tools to provide enterprise-level data management; SQL Server database engine provides a more secure and reliable solution for relational data and structured data. storage function.
- SQL 15938 2020-03-23 09:08:50
-
- Which data manipulation statement in SQL does not include?
- Data operation statements in sql do not include the "CHANGE" statement. "CHANGE" is used to rename fields and cannot modify field types and constraints; data operation statements in sql include "INSERT", "DELETE", and "UPDATE".
- SQL 14393 2020-03-14 10:26:46
-
- How to use exists in oracle
- The usage of exists in Oracle: 1. exists is followed by a subquery; 2. The function of exists is to check whether the result of the subquery is true. If it is true, the outer SQL statement is executed; 3. If the subquery is false, then Return false.
- SQL 14406 2020-03-06 17:56:03
-
- What is the Oracle table creation statement?
- Oracle table creation statement is CREATE TABLE tablename(column_name datatype). Where tablename is the name of the table to be created, column_name is the field name, and datatype is the field type.
- SQL 16474 2020-03-02 15:44:20
-
- How to modify table name in oracle
- How to modify the table name in Oracle: 1. Use alter table oldname rename to newname to modify the table name; 2. Use rename oldname to newname. This method can only modify tables under your own schema, etc.
- SQL 7175 2020-03-02 15:37:18
-
- How to delete table data in oracle
- How to delete table data in Oracle: 1. Use "truncate table table name" to delete all data in the table, which is fast, but cannot be deleted according to conditions; 2. Use "delete from table name where condition" to delete table data, which can be deleted according to conditions. , but slow.
- SQL 21522 2020-02-29 11:58:25
-
- How to modify field length in oracle
- How Oracle modifies the field length: Use the modify keyword to modify the field length. The format is: "alter table table name modify field name data type (length)".
- SQL 38796 2020-02-29 11:33:25
Recommended Articles
Tool Recommendations
jQuery enterprise message form contact code
jQuery enterprise message form contact code is a simple and practical enterprise message form and contact us introduction page code.
form button
2024-02-29
HTML5 MP3 music box playback effects
HTML5 MP3 music box playback special effect is an mp3 music player based on HTML5 css3 to create cute music box emoticons and click the switch button.
Player special effects
2024-02-29
HTML5 cool particle animation navigation menu special effects
HTML5 cool particle animation navigation menu special effect is a special effect that changes color when the navigation menu is hovered by the mouse.
Menu navigation
2024-02-29
jQuery visual form drag and drop editing code
jQuery visual form drag and drop editing code is a visual form based on jQuery and bootstrap framework.
form button
2024-02-29
Organic fruit and vegetable supplier web template Bootstrap5
An organic fruit and vegetable supplier web template-Bootstrap5
Bootstrap template
2023-02-03
Bootstrap3 multifunctional data information background management responsive web page template-Novus
Bootstrap3 multifunctional data information background management responsive web page template-Novus
backend template
2023-02-02
Real estate resource service platform web page template Bootstrap5
Real estate resource service platform web page template Bootstrap5
Bootstrap template
2023-02-02
Simple resume information web template Bootstrap4
Simple resume information web template Bootstrap4
Bootstrap template
2023-02-02
Cute summer elements vector material (EPS PNG)
This is a cute summer element vector material, including the sun, sun hat, coconut tree, bikini, airplane, watermelon, ice cream, ice cream, cold drink, swimming ring, flip-flops, pineapple, conch, shell, starfish, crab, Lemons, sunscreen, sunglasses, etc., the materials are provided in EPS and PNG formats, including JPG previews.
PNG material
2024-05-09
Four red 2023 graduation badges vector material (AI EPS PNG)
This is a red 2023 graduation badge vector material, four in total, available in AI, EPS and PNG formats, including JPG preview.
PNG material
2024-02-29
Singing bird and cart filled with flowers design spring banner vector material (AI EPS)
This is a spring banner vector material designed with singing birds and a cart full of flowers. It is available in AI and EPS formats, including JPG preview.
banner picture
2024-02-29
Golden graduation cap vector material (EPS PNG)
This is a golden graduation cap vector material, available in EPS and PNG formats, including JPG preview.
PNG material
2024-02-27
Home Decor Cleaning and Repair Service Company Website Template
Home Decoration Cleaning and Maintenance Service Company Website Template is a website template download suitable for promotional websites that provide home decoration, cleaning, maintenance and other service organizations. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-05-09
Fresh color personal resume guide page template
Fresh color matching personal job application resume guide page template is a personal job search resume work display guide page web template download suitable for fresh color matching style. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-29
Designer Creative Job Resume Web Template
Designer Creative Job Resume Web Template is a downloadable web template for personal job resume display suitable for various designer positions. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28
Modern engineering construction company website template
The modern engineering and construction company website template is a downloadable website template suitable for promotion of the engineering and construction service industry. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28
