Introduction to Oracle SQL | Oracle SQL Tutorial
Oracle database is a relational database management system.
It is known as Oracle database, OracleDB or simply Oracle. It is produced and marketed by Oracle Corporation.
It is known as Oracle database, OracleDB or simply Oracle. It is produced and marketed by Oracle Corporation.
Oracle database is the first database designed for enterprise grid computing. The enterprise grid computing provides the most flexible and cost effective way to manage information and applications.
Different editions of Oracle database
Following are the four editions of the Oracle database.
- Enterprise Edition: It is the most robust and secure edition. It offers all features, including superior performance and security.
- Standard Edition: It provides the base functionality for users that do not require Enterprise Edition's robust package.
- Express Edition (XE): It is the lightweight, free and limited Windows and Linux edition.
- Oracle Lite: It is designed for mobile devices.
The Oracle Corporation
Oracle Corporation is the largest software company in the field of database business. Its relational database was the first to support SQL which has since become the industry standard.
Oracle database is one of the most trusted and widely used relational database engines. The biggest rival of Oracle database is Microsoft's SQL Server.
History of Oracle
Oracle was originally developed by Lawrence Ellison (Larry Ellision) and his two friends and former co-worker in 1977. Oracle DB runs on the most major platforms like Windows, UNIX, Linux and Mac OS.
Oracle String Functions
Function | Description |
---|---|
ASCII | Returns the number code that represents the specified character |
ASCIISTR | Converts a string in any character set to an ASCII string using the database character set |
CHR | Returns the character based on the number code |
COMPOSE | Returns a Unicode string |
CONCAT | Allows you to concatenate two strings together |
Concat with || | Allows you to concatenate two or more strings together |
CONVERT | Converts a string from one character set to another |
DECOMPOSE | Accepts a string and returns a Unicode string |
DUMP | Returns a varchar2 value that includes the datatype code, the length in bytes, and the internal representation of the expression |
INITCAP | Sets the first character in each word to uppercase and the rest to lowercase |
INSTR | Returns the location of a substring in a string |
INSTR2 | Returns the location of a substring in a string, using UCS2 code points |
INSTR4 | Returns the location of a substring in a string, using UCS4 code points |
INSTRB | Returns the location of a substring in a string, using bytes instead of characters |
INSTRC | Returns the location of a substring in a string, using Unicode complete characters |
LENGTH | Returns the length of the specified string |
LENGTH2 | Returns the length of the specified string, using UCS2 code points |
LENGTH4 | Returns the length of the specified string, using UCS4 code points |
LENGTHB | Returns the length of the specified string, using bytes instead of characters |
LENGTHC | Returns the length of the specified string, using Unicode complete of characters |
LOWER | Converts all letters in the specified string to lowercase |
LPAD | Pads the left-side of a string with a specific set of characters |
LTRIM | Removes all specified characters from the left-hand side of a string |
NCHR | Returns the character based on the number code in the national character set |
REGEXP_INSTR | Returns the location of a regular expression pattern in a string |
REGEXP_REPLACE | Allows you to replace a sequence of characters in a string with another set of characters using regular expression pattern matching |
REGEXP_SUBSTR | Allows you to extract a substring from a string using regular expression pattern matching |
REPLACE | Replaces a sequence of characters in a string with another set of characters |
RPAD | Pads the right-side of a string with a specific set of characters |
RTRIM | Removes all specified characters from the right-hand side of a string |
SOUNDEX | Returns a phonetic representation (the way it sounds) of a string |
SUBSTR | Allows you to extract a substring from a string |
TRANSLATE | Replaces a sequence of characters in a string with another set of characters |
TRIM | Removes all specified characters either from the beginning or the end of a string |
UPPER | Converts all letters in the specified string to uppercase |
VSIZE | Returns the number of bytes in the internal representation of an expression |
Oracle Numeric Functions
Function | Description |
---|---|
ABS | Returns the absolute value of a number |
ACOS | Returns the arc cosine of a number |
ASIN | Returns the arc sine of a number |
ATAN | Returns the arc tangent of a number |
ATAN2 | Returns the arc tangent of n and m |
AVG | Returns the average value of an expression |
BITAND | Returns an integer representing an AND operation on the bits of expr1 and expr2 |
CEIL | Returns the smallest integer value that is greater than or equal to a number |
COS | Returns the cosine of a number |
COSH | Returns the hyperbolic cosine of a number |
COUNT | Returns the count of an expression |
EXP | Returns e raised to the power of number |
FLOOR | Returns the largest integer value that is equal to or less than a number |
GREATEST | Returns the greatest value in a list of expressions |
LEAST | Returns the smallest value in a list of expressions |
LN | Returns the natural logarithm of a number |
LOG | Returns the natural logarithm of a number to a specified base |
MAX | Returns the maximum value of an expression |
MEDIAN | Returns the median of an expression |
MIN | Returns the minimum value of an expression |
MOD | Returns the remainder of n divided by m |
POWER | Returns m raised to the nth power |
REGEXP_COUNT | Counts the number of times that a pattern occurs in a string |
REMAINDER | Returns the remainder of m divided by n |
ROUND | Returns a number rounded to a certain number of decimal places |
ROWNUM | Returns a number that represents the order that a row is |
SIGN | Returns a value indicating the sign of a number |
SIN | Returns the sine of a number |
SQRT | Returns the square root of a number |
SUM | Returns the summed value of an expression |
TAN | Returns the tangent of a number |
TANH | Returns the hyperbolic tangent of n |
TRUNC | Returns a number truncated to a certain number of decimal places |
Oracle Date Functions
Function | Description |
---|---|
ADD_MONTHS | Returns a date with a specified number of months added |
CURRENT_DATE | Returns the current date in the time zone of the current SQL session as set by the ALTER SESSION command |
CURRENT_TIMESTAMP | Returns the current date and time in the time zone of the current SQL session as set by the ALTER SESSION command |
DBTIMEZONE | returns the database time zone as a time zone offset or a time zone region name |
EXTRACT | Extracts a value from a date or interval value |
LAST_DAY | Returns the last day of the month based on a date value |
LOCALTIMESTAMP | Returns the current date and time in the time zone of the current SQL session as set by the ALTER SESSION command |
MONTHS_BETWEEN | Returns the number of months between date1 and date2 |
NEW_TIME | Converts a date from time zone1 to a date in time zone2 |
NEXT_DAY | Returns the first weekday that is greater than a date |
ROUND | Returns a date rounded to a specific unit of measure |
SESSIONTIMEZONE | Returns the current session's time zone as a time zone offset or a time zone region name |
SYSDATE | Returns the current system date and time on your local database |
SYSTIMESTAMP | Returns the current system date and time (including fractional seconds and time zone) on your local database |
TRUNC | Returns a date truncated to a specific unit of measure |
TZ_OFFSET | Returns the time zone offset of a value |
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