What is Coalesce Function Coalesce Function is a useful function in oracle and it is very useful when we want to return first non null values in the list.This SQL tutorial provides explanations, examples for Coalesce Function in Oracle and Difference between Coalesce & NVL expr1 : This is returned if it is not nullexpr2: […]
How to use NVL() function in Oracle
This Oracle SQL tutorial provides explanations, examples for NVL function in Oracle What is NVL() function in Oracle NVL function in Oracle is a nesting function which is used to substitute null values with certain values In the above syntax expr1 : it is the source values or expression which may contain null. You can […]
Oracle PLSQL Block Structure and Types
Here we will be discussing about Oracle PLSQL Block Structure and types What is PL/SQL PL/SQL is Oracle’s proprietary extension to SQL that allowsfor procedural language capabilities. It gives all the features of modern software engineering such as data encapsulation, exception handling, information hiding and object orientation Why Use PLSQL 1) Integration with development tools […]
how to use foreign key in oracle
What is Foreign key Foreign key in Oracle is a way to relate multiple Tables. It is a cross-linking between the tables. A foreign key is a column or set of column which refers to the primary key or Unique key in the same table or another table Foreign key values are based on data […]
How to create not null constraint in oracle
What is Not Null constraint in oracle Not Null constraint in oracle are used to enforce not null values in the column in the table. So if you try to insert null into those column, it will throw error. How to create not null constraint Not null constraints are defined at the table creation or […]
how to use check constraint in oracle
Introduction Oracle Check constraint is used to enforce integrity rules based on logical expressions, such as comparisons. The logical expressions used should return the boolean value. Example A CHECK constraint on employee salaries so that no salary value is greater than 100000. A CHECK constraint on department locations so that only the locations “DELHI”, “PATNA”, […]
