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- How to express not equal in Oracle
- The inequality operator in Oracle is represented by "<>" and is used to compare whether two values are equal and return TRUE or FALSE. For example, SELECT product_id, product_name FROM products WHERE product_price <> 10 returns products whose price is not equal to 10.
- Oracle 468 2024-05-07 14:03:14
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- What does desc mean in oracle
- The DESC (DESCRIBE) command describes the structure of a table or view in an Oracle database, providing information about columns, data types, size, nullability, and other details. The specific steps are as follows: Use syntax: DESC table_name; Return information: column name, data type, size, nullability, default value, constraints.
- Oracle 393 2024-05-07 14:00:26
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- Usage of any in oracle
- ANY in Oracle is used to check if there is a matching record in a subquery. It applies a subquery to each row in a table, returning TRUE or FALSE to indicate whether there is a match. Specific usage includes: checking matching records: determining whether subquery conditions are met. Aggregation query: Calculate the number of records that meet the conditions. WHERE clause in subquery: Specify the conditions in the WHERE clause of the subquery.
- Oracle 792 2024-05-07 13:57:17
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- What to use to connect strings in oracle
- There are five ways to concatenate strings in Oracle: 1. Plus (+) operator; 2. CONCAT function; 3. || operator (Oracle 12c and later); 4. DBMS_LOB.CONCAT function (LOB data type ); 5. Combine INSTR and SUBSTR functions. Choose the most appropriate method based on your needs.
- Oracle 680 2024-05-07 13:51:15
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- Function of select statement in oracle
- The SELECT statement retrieves data from an Oracle table. Functions include: Data retrieval: Select data from a column. Column selection: Specify the columns to retrieve or use (*) to retrieve all columns. Calculation: Perform calculations and return results, such as sums or averages. Conditional filtering: Use the WHERE clause to filter results by condition. Sorting: Use the ORDER BY clause to sort the results by column. Grouping: Use the GROUP BY clause to group results by columns and aggregate data. Join: Use the JOIN clause to join data from multiple tables.
- Oracle 1008 2024-05-07 13:45:24
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- How to write division in oracle
- Division operations in Oracle involve two operators: / (division) and MOD (remainder). The division operator / is used to calculate the quotient (floating point number), while the MOD operator is used to calculate the remainder (integer). The choice of operator depends on what is being calculated: / for commercial, MOD for remainder. It should be noted that the divisor cannot be 0, and the result of the MOD operator has the same sign as the divisor and is always a non-negative integer.
- Oracle 1165 2024-05-07 13:39:15
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- Function to update one column to another column in oracle
- Oracle provides the UPDATE() function and a series of other column update functions, including NVL(), COALESCE(), GREATEST(), and LEAST(), for updating one column to the value of another column. First determine the column to be updated, then find the column from which the updated value is to be obtained, and finally write the UPDATE() function to update the column.
- Oracle 774 2024-05-07 13:33:14
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- How to find the sum of each department using the sum function in Oracle
- The SUM function in Oracle can be used to calculate the sum of a set of numbers. To calculate the sum of each department, you need to: determine the column to be summarized, usually a numeric or decimal type (such as total sales or order quantity); use the GROUP BY clause Group data by department; use the SUM function in a SELECT statement to summarize the values of the columns in each group.
- Oracle 332 2024-05-07 13:30:22
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- How to express an integer with two decimal points in Oracle
- There are four ways to complete an integer to two decimal places in Oracle: using the TO_CHAR() function, using the LPAD() and SUBSTR() functions, using the TO_NUMBER() and TRUNC() functions, or using the ROUND() function.
- Oracle 544 2024-05-07 13:27:16
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- How to set the character size to 10 digits for reserved integers in Oracle
- The character size of numeric fields in Oracle can be set with NUMBER(char size, precision), where the precision of integers is 0. For numeric fields that need to store 10-digit integers, you can follow the steps below: 1. Create a table and set the character size of the numeric field to 10; 2. Insert 10-digit integer data; 3. Verify that the character size is correctly set to 10 digits.
- Oracle 268 2024-05-07 13:24:15
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- How to use translate in oracle
- The TRANSLATE function in Oracle replaces a character or set of characters in a string. Syntax: TRANSLATE(string, from_list, to_list). Parameters: string (input string), from_list (character or character set to be replaced), to_list (replacement character or character set). Usage: Traverse the characters in from_list, find matches in string and replace them with the corresponding characters in to_list. Examples: Convert lowercase letters to uppercase letters, convert numbers to asterisks, replace specific characters with other characters.
- Oracle 611 2024-05-07 13:21:16
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- The difference between varchar and varchar2 in oracle
- VARCHAR and VARCHAR2 are both string data types in Oracle. The difference is: 1. VARCHAR allows NULL values, while VARCHAR2 does not; 2. VARCHAR ends with the implicit terminator "\0", while VARCHAR2 ends with the explicit terminator " ''" at the end; 3. VARCHAR storage overhead is small, and VARCHAR2 will additionally check the explicit terminator if it is large; 4. VARCHAR insertion and update efficiency is high, while VARCHAR2 query efficiency is slightly lower. Recommendation: Use VARCHAR if NULL values are allowed or minimal storage overhead is required; NULL values are not allowed or
- Oracle 609 2024-05-07 13:18:18
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- The difference between varchar2 and char in oracle
- Key differences between VARCHAR2 and CHAR data types in Oracle: VARCHAR2: variable length, stores actual string length; CHAR: fixed length, padded with spaces. VARCHAR2: high storage and retrieval efficiency; CHAR: fast retrieval, low storage and update efficiency. VARCHAR2: comparison is based on actual content; CHAR: comparison is based on padding length. VARCHAR2: stores variable-length strings; CHAR: stores fixed-length strings.
- Oracle 836 2024-05-07 13:15:30
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- How to compare dates in oracle
- Oracle provides date comparison capabilities using operators such as = (equal), > (greater than), and < (less than). Use the DATE data type to store date values and support specifying comparison dates through arguments or bind variables. Additionally, AND and OR operators are provided for multiple date comparisons, as well as special rules for handling NULL values. Other date comparison-related functions provided by Oracle include ADD_MONTHS, ADD_DAYS, and BETWEEN.
- Oracle 331 2024-05-07 13:12:16
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- What are the functions of the spool command in Oracle?
- The SPOOL command in Oracle redirects query output to a file for persistence, debugging, or integration with other applications. The command syntax is: SPOOL [file_name] [APPEND | REPLACE], where file_name specifies the output file, APPEND appends the output, and REPLACE overwrites the existing file.
- Oracle 779 2024-05-07 13:09:14
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