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- count usage in oracle
- The COUNT function is used to count the number of rows in the table that meet the conditions. Syntax: COUNT(DISTINCT|ALL expression); where: DISTINCT counts unique values, ALL counts all values. Usage includes counting the number of all rows, the number of non-null values in a specific column, the number of rows that meet the condition, and the number of unique values.
- Oracle 724 2024-05-02 23:48:58
- The difference between concat function and || in oracle
- CONCAT and || are both string connection functions in Oracle. The main differences are: function syntax (CONCAT with parentheses, || without), NULL processing (CONCAT returns NULL, || returns an empty string), performance (CONCAT is more Slow) and usage scenarios (CONCAT is used for multi-string concatenation that may have NULL, || is used for small-string concatenation without NULL).
- Oracle 970 2024-05-02 23:48:37
- How to use concat function in oracle
- The CONCAT function in Oracle is used to concatenate strings: Concatenate multiple strings: CONCAT(string1, string2, ...) Concatenate strings and column values: CONCAT('text', column name) Concatenate strings using operators: 'string1' || 'string2' || ...Note: If any string is NULL, the result is NULL; up to 254 strings can be concatenated.
- Oracle 932 2024-05-02 23:46:11
- Tochar usage in oracle
- The TO_CHAR function converts an Oracle expression to a character value, formatting the output to suit your needs. Use a string template (format_mask) to define the format, including text characters, format modifiers, and placeholders. Format masks are case-sensitive, and placeholders require the correct format modifier.
- Oracle 1012 2024-05-02 23:45:33
- How to add two decimal points to an integer in Oracle?
- There are two ways to represent integers with two decimal points in Oracle: scientific notation (such as 100 * 10^-2 = 0.01) and the TO_CHAR function (such as TO_CHAR(100, 'fm9999999999990.99') = 0.01).
- Oracle 560 2024-05-02 23:42:52
- How to use case in oracle
- The CASE statement in Oracle is a tool for conditional evaluation, its usage includes: specifying the condition to be evaluated (WHEN). The action (THEN) to perform if the condition is true. If all conditions are false, perform the default action (ELSE, optional).
- Oracle 834 2024-05-02 23:42:36
- What does number(10,4) mean in oracle
- The NUMBER(10,4) data type in Oracle stores numeric values with a precision of 4 decimal places, ranging from -9999999999.9999 to 9999999999.9999. The maximum length of the integer part is 6 digits, and the maximum length of the decimal part is 4 digits.
- Oracle 842 2024-05-02 23:42:17
- Usage of to_date in oracle
- The TO_DATE function in Oracle converts a string to the DATE data type. Syntax: TO_DATE(string, format_mask). format_mask is a placeholder mask that specifies the format of the date and time portion of the string. Placeholders include YYYY (year), MM (month), DD (day), HH (hour), MI (minute), SS (second), FF (billionth of a second). For example, TO_DATE('2023-03-08', 'YYYY-MM-DD') converts "2023-03-08" to DATE.
- Oracle 833 2024-05-02 23:40:00
- Usage of todate function in oracle
- The TO_DATE function converts a string to an Oracle date type. It takes two parameters: the string expression to convert and a format mask specifying the string format. Common format masks include 'DD-MON-YY' (e.g. '12-JAN-23'), 'YYYY-MM-DD' (e.g. '2023-01-12') and 'HH24:MI:SS' (e.g. '12-JAN-23') For example '13:30:00'). Use a format mask to select the correct format to convert a string into a date value.
- Oracle 530 2024-05-02 23:39:40
- How to use on in oracle
-
The ON clause joins rows in a table, creating a matching relationship based on common columns. It is used in table join operations, and the syntax is: ON
. This condition compares columns in the table to establish the connection. - Oracle 659 2024-05-02 23:39:19
- Usage of regexp_replace in oracle
- The REGEXP_REPLACE function in Oracle replaces matching parts of a string using regular expressions: Syntax: REGEXP_REPLACE(input_string, pattern, replacement) Usage example: Replace all numbers with X Replace all vowels with A Replace with capturing groups Advanced usage: Replace Count ignore case multiline mode
- Oracle 851 2024-05-02 23:36:51
- How to delete a field in a table in oracle
- Deleting a field from a table in Oracle requires the following steps: Determine the field to delete. Use the ALTER TABLE table_name DROP COLUMN column_name statement. Commit changes. After a field is deleted, it will not be restored and dependencies need to be checked and adjusted.
- Oracle 835 2024-05-02 23:36:16
- What is the length of number in oracle
- The Oracle NUMBER data type has a maximum length of 38 bits, including the decimal point and decimal places: 38 bits for the integer part and 128 bits for the fractional part. Precision is the number of digits that can be stored after the decimal point and ranges from 0 to 128. When choosing the appropriate length, consider data range, accuracy requirements, and storage space.
- Oracle 550 2024-05-02 23:33:59
- What does sp mean in oracle?
- SPSP in Oracle stands for Stored Procedure and is used to encapsulate complex blocks of SQL statements into reusable modules. The advantages of stored procedures include: code reusability, improved performance, improved data integrity, and improved security.
- Oracle 920 2024-05-02 23:33:40
- Extend usage in oracle
- Oracle's EXTEND operator is used to allocate storage space to an existing partition in a partitioned table, increasing its size. Syntax: ALTER TABLE table_name EXTEND PARTITION partition_name FOR { storage (size) | MAXSIZE (size) }. Parameters include partition table name, partition name, storage space size or maximum storage space size, etc. The EXTEND operator extends indexes with USING INDEXES and excludes partitions with NOT INCLUDING PARTITION. Execute EX online or offline
- Oracle 263 2024-05-02 23:33:21
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