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With SQL how can you delete the records where the FirstName is Peter in the Persons Table?
To delete records where FirstName is Peter in the Persons Table, you can use the following SQL query: DELETE FROM Persons WHERE FirstName = 'Peter';
Sql command to retrive all data froma table?
The SQL command that can be used to retrieve all data from a table is the SELECT Ex: Let us say we have a table called employee_master which contains 3 columns emp_name, emp_number, date_of_joining you can retrieve all the data by using the below command SELECT * FROM employee_master or SELECT emp_name, emp_number, date_of_joining FROM employee_master
What virtual table in a database is known as a?
A view table.
What is the Difference between view and index in sql?
In SQL, a view is a virtual table based on the result set of a SQL statement, which can be queried like a table. An index is a data structure that improves the speed of data retrieval by providing quick access to the rows in a table based on the indexed column(s). Views are used to simplify query complexity, while indexes are used to optimize data retrieval performance.
What is Outer Join SQL used for according to Wikipedia?
Outer Join in SQL is used to retrieve all records from one table and only matching records from another table. It helps to retrieve data from related tables even if there are no matching records in one of the tables.
Create view in SQL?
create view vw_active_employee as select * from employee where status = 'Active' after creating the view, view can be used as a table to see active employee. e.g. select * from vw_active_employee Basically we save sql as a database object, so that we can use that in future as a virtual table.
What is hash table in sql?
temp table
What is the name of two DDL operations in SQL?
Some of the operations performed in DDL in sql are creation of table,alteration of table,truncate a table, drop a table
What is virtual function table?
A virtual function table is a table of pointers to functions.
What is the different between a view and a create view?
View is a virtual table that do not have any data of its own but have data that is derived from another table called base table. Create view is the command used to create a view (virtual table).
What is the function of a Foreign Key in SQL?
A Foreign Key in SQL is used to establish a relationship between two tables. It ensures referential integrity by enforcing that values in a column (or columns) in one table must match the values in a primary key in another table. This helps maintain consistency and data integrity across linked tables.
How a primary key is fixed in a sql table?
A primary key field in a sql table is created using the PRIMARY KEY keyword. ex: CREATE TABLE tbl_employee ( emp_num VARCHAR(10), emp_name VARCHAR(100), PRIMARY KEY (emp_num)) The above script creates a table called tbl_employee and sets the emp_num field as the primary key
Does a new table exist after joins in sql?
no. a new table does not exist after a join command. All that is doing is temporarily pulling the data from the tables. If this command was one that you would want to do often, you can create a VIEW, which is a virtual table. It is an object that pulls data from one or more tables based on your search criteria.
What does SQL CREATE VIEW achieve?
SQL CREATE VIEW achieves the creation of a table or tables in the SQL database. One can then create tables to the purpose they desire and fill them in with information.
How do you join a table to itself in sql?
using aliases: SELECT a.some_fields, b.other_fields FROM table a, table b WHERE a.foreign_key=b.primary_key;
In VB.NET what method is used to modify a table?
SQL UPDATE statement is used to modify a record in a table.
How do you retrieve data from table in sql by selecting month?
select * from "table-name" where month="required month";
