current location：Home > Technical Articles > Database > Oracle
- Direction：
- All web3.0 Backend Development Web Front-end Database Operation and Maintenance Development Tools PHP Framework Daily Programming WeChat Applet Common Problem Other Tech CMS Tutorial Java System Tutorial Computer Tutorials Hardware Tutorial Mobile Tutorial Software Tutorial Mobile Game Tutorial
- Classify：
-
- Usage of regexp_like in oracle
- The REGEXP_LIKE function in Oracle is used to compare whether a string matches a regular expression and returns a Boolean value: Syntax: REGEXP_LIKE(string, regexp, [condition]) Parameters: String, regular expression pattern, optional matching condition ( Default: simple comparison) Usage: Specify strings and regular expression patterns, such as REGEXP_LIKE('string', 'pattern') Example: Match starting with "ABC", containing "XYZ" or case-insensitively matching "PATTERN" string
- Oracle 498 2024-05-03 00:09:33
-
- What is the function that intercepts from right to left in Oracle?
- Oracle's LTRIM function is used to truncate all whitespace characters from the right side of a string, including spaces, tabs, newlines, and carriage returns. It returns the trimmed string, or the original string if the string does not contain whitespace.
- Oracle 929 2024-05-03 00:09:15
-
- How to use tochar in oracle
- The Oracle TO_CHAR function converts a number, date, or time value to a string. The format string specifies the output format, including date, time, and number format elements. Common date format elements include "%Y" (year) and "%m" (month), and number format elements include "9" (number) and "." (decimal point). For example: Convert date to "YYYY-MM-DD": SELECT TO_CHAR(sysdate, 'YYYY-MM-DD') FROM dual;
- Oracle 989 2024-05-03 00:06:58
-
- How to use explain in oracle
- The EXPLAIN command in Oracle is used to analyze the execution plan of a SQL statement. The method of use is to add the EXPLAIN keyword before the SQL statement. EXPLAIN results contain information such as ID, operator type, row count estimate, cost estimate, output row count estimate, access predicates, and filter predicates, which can be used to optimize query performance, identify costly operators, and tables that may benefit from optimization techniques.
- Oracle 700 2024-05-03 00:06:39
-
- Can date type fields in Oracle be empty characters?
- No, DATE type fields in Oracle do not allow null characters; it enforces a valid date value, and null date values are interpreted as NULL.
- Oracle 826 2024-05-03 00:03:48
-
- Can the date type in oracle be empty?
- Can DATE type be null in Oracle? Yes, you can use NULL values to represent empty date values.
- Oracle 1028 2024-05-03 00:03:34
-
- How to enter date type in oracle
- There are three ways to enter the DATE type in Oracle: direct input, using the TO_DATE function, and using the CAST function. Direct input must follow the YYYY-MM-DD HH24:MI:SS format; the TO_DATE function syntax is TO_DATE(string, formatted string); the CAST function syntax is CAST(string AS DATE).
- Oracle 950 2024-05-03 00:03:16
-
- What is the job in oracle for?
- Jobs in Oracle are predefined tasks that are automatically executed at a specified time, such as triggering operations, sending notifications, calling programs, and maintaining data. When creating a Job, you need to define the name, schedule, actions, and status, and use ENABLE or DISABLE to control the activity status. Job benefits include automating tasks, scheduling tasks, parallel processing, and monitoring and control through tools.
- Oracle 446 2024-05-03 00:01:09
-
- What is the difference between nvl in oracle and nvl in hive
- Oracle and Hive's NVL functions are used to handle NULL values, but there are differences: NULL handling: Hive NVL can handle NULL replacement_value, while Oracle NVL cannot. Nested NULL checks: Hive NVL can check for NULL in nested expressions, while Oracle NVL cannot.
- Oracle 1169 2024-05-03 00:00:49
-
- substr usage in oracle
- The SUBSTR function in Oracle extracts a specific number of characters from a string. The syntax is SUBSTR(string, start_position, length), where string is the target string, start_position is the starting extraction position (starting from 1), and length is the number of characters extracted. A negative starting position means counting down from the end of the string, and omitting the length parameter extracts all characters from the starting position to the end of the string.
- Oracle 1009 2024-05-03 00:00:31
-
- Instr usage in oracle
- The function of the INSTR function in Oracle is to find the starting position of a substring in a string. The syntax is INSTR(string, substring, [start_position]). It returns the starting position of the matching substring. If it is not found, it returns 0. Among them, string is the string to be searched, substring is the substring to be found, and start_position is the starting position of the search (optional). The INSTR function is not case-sensitive. By default, it searches from the beginning of the string. It supports searching from the specified position. If the substring appears multiple times in the string, only the starting position of the first matching item will be returned. If the string or subword
- Oracle 1041 2024-05-02 23:54:57
-
- How to use insert in oracle
- The INSERT statement in Oracle is used to insert new rows into the table. The syntax is: INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...), where table_name is the table name, column1, column2, ... is the column name, value1, value2, ... are values. Multiple rows can be inserted. NULL values must be inserted. The values must be compatible with the data type. Repeated primary key values cannot be inserted. The defined trigger will be triggered. If not Specifying column names will insert them in table column order.
- Oracle 1085 2024-05-02 23:54:37
-
- How to use if function in oracle
- The IF function in Oracle is a control flow function used to execute blocks of code based on conditions. Its syntax is as follows: IF (condition) THEN -- If the condition is true, execute this code block ELSE -- If the condition is false, execute this code block END IF;
- Oracle 1257 2024-05-02 23:54:20
-
- How to write when and then in oracle
- In Oracle, the WHEN and THEN syntax is used in CASE expressions to return different values based on a condition: The WHEN clause specifies the condition to be evaluated. The THEN clause specifies the value to be returned if the condition is true. The ELSE clause (optional) specifies the value returned when all WHEN conditions are false.
- Oracle 1218 2024-05-02 23:51:52
-
- Usage of lag (function and lead (function) in oracle
- The LAG() and LEAD() functions in Oracle obtain the value of the row before (LAG()) or after (LEAD()) the specified row offset from the current row. They are used to analyze time series data and calculate moving averages. The LAG() function returns the value of the previous row, and the LEAD() function returns the value of the subsequent row. The offset can be positive or negative, and returns a default value if it is outside the table range.
- Oracle 1224 2024-05-02 23:51:36
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
