Introduction of TCL Statements TCL statements play a crucial role in managing transactions in a DBMS, providing mechanisms to ensure data integrity and consistency. Definition In a Database Management System (DBMS), Transaction Control Language (TCL) statements are used to manage the changes made by Data Manipulation Language (DML) statements. TCL (Transaction Read more…
Introduction SQL stands for ‘Structured Query Language’. SQL is pronounced as ‘Sequel’. SQL statements are like simple English imperative sentence. Features SQL is a query language used to retrieve and manipulate data in various ways as per need of the programmer in a RDBMS. There are 5 common operations performed by the Read more…
Currently Used SQL Keywords NB : SQL Keywords can be used as Identifiers in our query by putting them inside big bracket such as [ADD], [PERCENT], [ALL] etc. ADD EXCEPT PERCENT ALL EXEC PLAN ALTER EXECUTE PRECISION Read more…
Example : How to Export Oracle 10g/11g Database file or How to create dump(.dmp) file in Oracle10g/11g . Example : How to Export selected tables in Oracle10g/11g Database file as dump(.dmp) file. Example : How to Import dump(.dmp) file into Oracle 10g/11g.
Alter Table Statement Definition : Alter Table statement is used to change the structure of an existing table of a database i.e. this statement specifies how to add one or multiple new columns/fields/attributes, modify one or more existing columns/fields/attributes , drop or delete the existing columns from a table, rename Read more…
Definition : This statement is used to modify/change/update the existing record/s or data in the database. Syntax : UPDATE table–name SET(column–name1=value1, column–name2 =value2, column–name3=value3, column–name4=value4, column–name5=value5 ) ; Example : UPDATE employee SET(emp_id=”125M”, emp_name=”Rahman”, emp_addr =”Kolkata”, emp_dept=”Manager”, emp_dob=”05/22/2020″, emp_sal=20500, emp_mob=9334582186); UPDATE employee SET(emp_name=”Rahman”, emp_addr =”Kolkata”, emp_dept=”Manager”, emp_dob=”05/22/2020″, emp_sal=20500, emp_mob=9334582186 where emp_id= “105M”);
Definition : This statement is used to remove one or more records permanently from the database table. Syntax : DELETE table-name; DELETE table-name where condition; Example : Problem : How to remove all data/records from a table permanently. SQL> Delete from employee; SQL> Delete * from employee; Problem : How Read more…
SELECT STATEMENT Basic Select Syntax : SELECT column_name1,column_name2… column_name_n FROM table-name[WHERE Clause][GROUP BY clause][HAVING clause][ORDER BY clause]; The SELECT query statement is used to retrieve stored data from a database in the form of table-like structure called result set. It is one of the largest use query/statement. Example : How Read more…
Definition : Insert into statement is used to add new or fresh record/s into an existing database table. Syntax : INSERT INTO table-name (field or attribute or column-name1, column-name2, column-name3, column-name4, column-name5) VALUES (value1, value2, value3, value4, value5 );(Press Enter) Example : For more Select query use this link
Create Table Definition : This statement creates a new/fresh table with various column or field names and respective datatypes in a database. Syntax : CREATE TABLE schema_name.table_name (column_name1 data_type1 column_constraint1, column_name2 data_type2 column_constraint2, . . . table_constraints ); CREATE TABLE table_name ( column_name1 data_type1 column_constraint1, column_name2 data_type2 column_constraint2, Read more…