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오라클 EMPTY_BLOB() 오라클 EMPTY_CLOB() EMPTY_BLOB and EMPTY_CLOB return an empty LOB locator that can be used to initialize a LOB variable or, in an INSERT or UPDATE statement, to initialize a LOB column or attribute to EMPTY. EMPTY means that the LOB is initialized, but not populated with data. An empty LOB is not the same as null LOB, and an empty CLOB is not the same as a LOB containing a string o..

오라클 DENSE_RANK() - 순위를 정하기 좋은 함수 같다. 그룹내에 정렬된 데이타의 순위를 매기기 좋은 함수 정도 ?? Aggregate Syntax 생략 Analytic Syntax DENSE_RANK() OVER(PARTION BY ~~~ ORDER BY ~~~) DENSE_RANK computes the rank of row in an ordered group of rows and returns the rank as a NUMBER. Then ranks are consecutive integers beginning with 1. The larget rank value is the number of unique values returned by the queyr. Rank values are ..

오라클 DELETEXML(); DELETEXML deletes the node or nodes matched by the XPATH expression the the target XML.

오라클 DECODE() DECODE(expr, search, result, default) DECODE(expr, search, result, search, result, search, result, default); 와 같은 형태도 가능하여 여러개를 한번에 비교할 수 있다. DECODE compares expr to each search value one by one. If expr is equals to a search, then Oracle Database returns the corresponding result. If no match is found, then Oracle returns default. If default is omitted, then Oracle returns null. The..

오라클 CURRENT_TIMESTAMP() CURRENT_TIMESTAMP(precision) CURRENT_TIMESTAMP returns the current date and time in the session time zone, in a value of data type TIMESTAMP WITH TIME ZONE. The time zone offset reflects the current local time of SQL session. If you omit precision, then the default is 6. The difference between this function and LOCALTIMESTAMP is the CURRENT_TIMESTAMP returns a TIMESTAMP W..

오라클 CURRENT_DATE() CURRENT_DATE returns the current date in the session time zone, in a value in the Gregorian calendar of data type DATE. SQL > SELECT SESSIONTIMEZONE, CURRENT_DATE FROM DUAL ; --> +09:00 2020/03/26 오전 10:40:48

오라클 COUNT() COUNT returns the number of rows returned by the query. You can use it as an aggregate or analytic function If you specity DISTINCT, then you can sepcify only the query_partition_clause of the analytic_clause. The order_by_clause and windowing_clause are not allowed. If you speify expr. then COUNT returns the number of rows where expr is not null. You can count either all rows, or on..

오라클 cos() COS returns the cosine of n (an angle expressed in radians). This function takes as an argument any numeric data type or any nonnumeric data type that can be implicitly converted to a numeric data type. If the argument is BINARY_FLOAT, then the function return BINARY_DOUBLE. Otherwise the function returns the same numeric data type as the argument. SQL > SELECT COS(180* 3.14159265359) ..