ROWNUM is one of the vital Numeric/Math functions of Oracle. It is used to get a number that represents the order in which a row from a table or joined tables is selected by the Oracle. The ROWNUM function is supported in the various versions of the Oracle/PLSQL, including, Oracle 12c, Oracle 11g, Oracle 10g, … Read more
REGEXP_COUNT is one of the vital Numeric/Math functions of Oracle. It is much like the COUNT function which is used to get the Count of an expression. But the difference is that the REGEXP_COUNT is used to get the Count of a regular expression pattern in a string. The REGEXP_COUNT function is supported in the … Read more
OUTER JOIN Oracle supports three major types of Outer joins namely, Left Outer Join, Right Outer Join and Full Outer Join. Left Outer Join: As the name suggests, the Left Outer Join query offers more benefits for the Left table, can also be understood as the First table and thus returns all the rows from … Read more
ORACLE UNION To combine the output sets of two or more Oracle SELECT statements, the Oracle UNION operator is used. During the combining process, the UNION operator removes the duplicate rows between the SELECT statements’ results. There are however two mandatory conditions for using the UNION operator in Oracle. Each SELECT statement must have the … Read more
ORACLE UPDATE To update the existing records in a table, the Oracle UPDATE statement is used. Syntax: To Update a table in simple steps. UPDATE table_name SET column_1 = expr_1, column_2 = expr_2, … column_n = expr_n WHERE conditions; Syntax: To Update Table by selecting records from another table. UPDATE table_name SET column_1 = (SELECT … Read more
ORACLE UNION ALL To combine the output sets of two or more Oracle SELECT statements, the Oracle UNION ALL operator is used. During the combining process, the UNION ALL operator does not remove the duplicate rows between the SELECT statements’ results, but returns all of them and this feature makes it different from the Oracle … Read more
ORACLE SELECT To fetch records from the tables and views stored in the database, the Oracle SELECT statement is used. Syntax: To select all fields from a table. SELECT * FROM table_name; Parameters: table_name: It is used to specify the name of the table from which you want to retrieve the records. Example: Selecting all … Read more
ORACLE QUERIES Select, Insert, Update, Delete, Drop, Alter table, and Create are the few queries among many that can be executed in an Oracle database. Oracle Select Query: Uses: To fetch records from the database. Syntax: To select records from a table. SELECT * from table_name; Example: SELECT * from students;SELECT * from students; Oracle … Read more
ORACLE INTERSECT To compare the rows of two or more Oracle SELECT statements, the Oracle INTERSECT operator is used. After the comparing process, the INTERSECT operator returns the common or intersecting records from the corresponding columns of the selected expressions. There are however two mandatory conditions for using the INTERSECT operator in Oracle. Each SELECT … Read more
ORACLE PROCEDURE A group of PL/SQL statements is called a procedure and what makes it unique is that it can be called by name. The call spec or the call specification is utilised to call a Java method or a third-generation language routine from SQL and PL/SQL, and to serve this purpose it specifies their … Read more